javaWeb狂神_09（smbms）

源码在最后

文章目录

- SMBMS(超市管理项目)

SMBMS(超市管理项目)

在这里插入图片描述

数据库：
在这里插入图片描述
项目如何搭建？
考虑是不是用maven？ jar包，依赖

搭建项目准备工作

搭建一个maven web 项目
配置Tomcat
测试项目是否能够跑起来
导入项目中需要的jar包;
jsp，Servlet，mysql驱动jstl，stand…
构建项目包结构
编写实体类
ROM映射:表-类映射

编写基础公共类
1、数据库配置文件（mysql5.xx和8.xx的编写有差异）

driver=com.mysql.jdbc.Driver
#在和mysql传递数据的过程中，使用unicode编码格式，并且字符集设置为utf-8
url=jdbc:mysql://127.0.0.1:3306/smbms?useSSL=false&useUnicode=true&characterEncoding=utf-8
user=root
password=root

     
      
      
     
      
      
       
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2、编写数据库的公共类

package dao;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

/**

操作数据库的基类–静态类
@author Administrator

*/
public class BaseDao {

<span class="token keyword">static</span><span class="token punctuation">{<!-- --></span><span class="token comment">//静态代码块,在类加载的时候执行</span>
	<span class="token function">init</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">private</span> <span class="token keyword">static</span> String driver<span class="token punctuation">;</span>
<span class="token keyword">private</span> <span class="token keyword">static</span> String url<span class="token punctuation">;</span>
<span class="token keyword">private</span> <span class="token keyword">static</span> String user<span class="token punctuation">;</span>
<span class="token keyword">private</span> <span class="token keyword">static</span> String password<span class="token punctuation">;</span>

<span class="token comment">//初始化连接参数,从配置文件里获得</span>
<span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">void</span> <span class="token function">init</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
	Properties params<span class="token operator">=</span><span class="token keyword">new</span> <span class="token class-name">Properties</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	String configFile <span class="token operator">=</span> <span class="token string">"database.properties"</span><span class="token punctuation">;</span>
	InputStream is<span class="token operator">=</span>BaseDao<span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">.</span><span class="token function">getClassLoader</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getResourceAsStream</span><span class="token punctuation">(</span>configFile<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
		params<span class="token punctuation">.</span><span class="token function">load</span><span class="token punctuation">(</span>is<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">IOException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	driver<span class="token operator">=</span>params<span class="token punctuation">.</span><span class="token function">getProperty</span><span class="token punctuation">(</span><span class="token string">"driver"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	url<span class="token operator">=</span>params<span class="token punctuation">.</span><span class="token function">getProperty</span><span class="token punctuation">(</span><span class="token string">"url"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	user<span class="token operator">=</span>params<span class="token punctuation">.</span><span class="token function">getProperty</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	password<span class="token operator">=</span>params<span class="token punctuation">.</span><span class="token function">getProperty</span><span class="token punctuation">(</span><span class="token string">"password"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token punctuation">}</span>   


<span class="token comment">/**
 * 获取数据库连接
 * @return
 */</span>
<span class="token keyword">public</span> <span class="token keyword">static</span> Connection <span class="token function">getConnection</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
	Connection connection <span class="token operator">=</span> null<span class="token punctuation">;</span>
	<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
		Class<span class="token punctuation">.</span><span class="token function">forName</span><span class="token punctuation">(</span>driver<span class="token punctuation">)</span><span class="token punctuation">;</span>
		connection <span class="token operator">=</span> DriverManager<span class="token punctuation">.</span><span class="token function">getConnection</span><span class="token punctuation">(</span>url<span class="token punctuation">,</span> user<span class="token punctuation">,</span> password<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">Exception</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		<span class="token comment">// TODO Auto-generated catch block</span>
		e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	
	<span class="token keyword">return</span> connection<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token comment">/**
 * 查询操作
 * @param connection
 * @param pstm
 * @param rs
 * @param sql
 * @param params
 * @return
 */</span>
<span class="token keyword">public</span> <span class="token keyword">static</span> ResultSet <span class="token function">execute</span><span class="token punctuation">(</span>Connection connection<span class="token punctuation">,</span>PreparedStatement pstm<span class="token punctuation">,</span>ResultSet rs<span class="token punctuation">,</span>
		String sql<span class="token punctuation">,</span>Object<span class="token punctuation">[</span><span class="token punctuation">]</span> params<span class="token punctuation">)</span> <span class="token keyword">throws</span> Exception<span class="token punctuation">{<!-- --></span>
	pstm <span class="token operator">=</span> connection<span class="token punctuation">.</span><span class="token function">prepareStatement</span><span class="token punctuation">(</span>sql<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator">&lt;</span> params<span class="token punctuation">.</span>length<span class="token punctuation">;</span> i<span class="token operator">++</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
		pstm<span class="token punctuation">.</span><span class="token function">setObject</span><span class="token punctuation">(</span>i<span class="token operator">+</span><span class="token number">1</span><span class="token punctuation">,</span> params<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	rs <span class="token operator">=</span> pstm<span class="token punctuation">.</span><span class="token function">executeQuery</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">return</span> rs<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token comment">/**
 * 更新操作
 * @param connection
 * @param pstm
 * @param sql
 * @param params
 * @return
 * @throws Exception
 */</span>
<span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">int</span> <span class="token function">execute</span><span class="token punctuation">(</span>Connection connection<span class="token punctuation">,</span>PreparedStatement pstm<span class="token punctuation">,</span>
		String sql<span class="token punctuation">,</span>Object<span class="token punctuation">[</span><span class="token punctuation">]</span> params<span class="token punctuation">)</span> <span class="token keyword">throws</span> Exception<span class="token punctuation">{<!-- --></span>
	<span class="token keyword">int</span> updateRows <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span>
	pstm <span class="token operator">=</span> connection<span class="token punctuation">.</span><span class="token function">prepareStatement</span><span class="token punctuation">(</span>sql<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator">&lt;</span> params<span class="token punctuation">.</span>length<span class="token punctuation">;</span> i<span class="token operator">++</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
		pstm<span class="token punctuation">.</span><span class="token function">setObject</span><span class="token punctuation">(</span>i<span class="token operator">+</span><span class="token number">1</span><span class="token punctuation">,</span> params<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	updateRows <span class="token operator">=</span> pstm<span class="token punctuation">.</span><span class="token function">executeUpdate</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">return</span> updateRows<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token comment">/**
 * 释放资源
 * @param connection
 * @param pstm
 * @param rs
 * @return
 */</span>
<span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">boolean</span> <span class="token function">closeResource</span><span class="token punctuation">(</span>Connection connection<span class="token punctuation">,</span>PreparedStatement pstm<span class="token punctuation">,</span>ResultSet rs<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
	<span class="token keyword">boolean</span> flag <span class="token operator">=</span> <span class="token boolean">true</span><span class="token punctuation">;</span>
	<span class="token keyword">if</span><span class="token punctuation">(</span>rs <span class="token operator">!=</span> null<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
		<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
			rs<span class="token punctuation">.</span><span class="token function">close</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			rs <span class="token operator">=</span> null<span class="token punctuation">;</span><span class="token comment">//GC回收</span>
		<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">SQLException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
			<span class="token comment">// TODO Auto-generated catch block</span>
			e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			flag <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>
	<span class="token punctuation">}</span>
	<span class="token keyword">if</span><span class="token punctuation">(</span>pstm <span class="token operator">!=</span> null<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
		<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
			pstm<span class="token punctuation">.</span><span class="token function">close</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			pstm <span class="token operator">=</span> null<span class="token punctuation">;</span><span class="token comment">//GC回收</span>
		<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">SQLException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
			<span class="token comment">// TODO Auto-generated catch block</span>
			e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			flag <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>
	<span class="token punctuation">}</span>
	<span class="token keyword">if</span><span class="token punctuation">(</span>connection <span class="token operator">!=</span> null<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
		<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
			connection<span class="token punctuation">.</span><span class="token function">close</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			connection <span class="token operator">=</span> null<span class="token punctuation">;</span><span class="token comment">//GC回收</span>
		<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">SQLException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
			<span class="token comment">// TODO Auto-generated catch block</span>
			e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			flag <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>
	<span class="token punctuation">}</span>
	
	<span class="token keyword">return</span> flag<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

. 3、编写字符编码过滤器

导入静态资源

登录功能实现

在这里插入图片描述

编写前端页面
设置首页
1.设置欢迎首页

  <welcome-file-list>
    <welcome-file>login.jsp</welcome-file>
  </welcome-file-list>

 
  
  
 
  
  
   
   1
   
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   3

编写dao层登录用户登录的接口

public User getLoginUser(Connection connection, String userCode) throws Exception;

 
  
  
 
  
  
   
   1

编写dao层接口的实现类

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

import dao.BaseDao;
import pojo.User;

public class UserDaoImpl implements UserDao{
//持久层只做查询数据库的内容
public User getLoginUser(Connection connection, String userCode) throws Exception{
//准备三个对象
PreparedStatement pstm = null;
ResultSet rs = null;
User user = null;
//判断是否连接成功
if(null != connection){
String sql = “select * from smbms_user where userCode=?”;
Object[] params = { userCode};
rs = BaseDao.execute(connection, pstm, rs, sql, params);
if(rs.next()){
user = new User();
user.setId(rs.getInt(“id”));
user.setUserCode(rs.getString(“userCode”));
user.setUserName(rs.getString(“userName”));
user.setUserPassword(rs.getString(“userPassword”));
user.setGender(rs.getInt(“gender”));
user.setBirthday(rs.getDate(“birthday”));
user.setPhone(rs.getString(“phone”));
user.setAddress(rs.getString(“address”));
user.setUserRole(rs.getInt(“userRole”));
user.setCreatedBy(rs.getInt(“createdBy”));
user.setCreationDate(rs.getTimestamp(“creationDate”));
user.setModifyBy(rs.getInt(“modifyBy”));
user.setModifyDate(rs.getTimestamp(“modifyDate”));
}
BaseDao.closeResource(null, pstm, rs);
}
return user;
}
}

业务层接口

//用户登录
public User login(String userCode, String userPassword);

 
  
  
 
  
  
   
   1
   
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业务层实现类

import java.sql.Connection;

//import org.junit.Test;

import dao.BaseDao;
import dao.user.UserDao;
import dao.user.UserDaoImpl;
import pojo.User;

public class UserServiceImpl implements UserService{
//业务层都会调用dao层.所以我们要引入Dao层（重点）
//只处理对应业务

<span class="token keyword">private</span> UserDao userDao<span class="token punctuation">;</span>
<span class="token keyword">public</span> <span class="token function">UserServiceImpl</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
	userDao <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">UserDaoImpl</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> User <span class="token function">login</span><span class="token punctuation">(</span>String userCode<span class="token punctuation">,</span>String userPassword<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
	<span class="token comment">// TODO Auto-generated method stub</span>
	Connection connection <span class="token operator">=</span> null<span class="token punctuation">;</span>
	<span class="token comment">//通过业务层调用对应的具体数据库操作</span>
	User user <span class="token operator">=</span> null<span class="token punctuation">;</span>
	<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
		connection <span class="token operator">=</span> BaseDao<span class="token punctuation">.</span><span class="token function">getConnection</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		user <span class="token operator">=</span> userDao<span class="token punctuation">.</span><span class="token function">getLoginUser</span><span class="token punctuation">(</span>connection<span class="token punctuation">,</span> userCode<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">Exception</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		<span class="token comment">// TODO Auto-generated catch block</span>
		e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span><span class="token keyword">finally</span><span class="token punctuation">{<!-- --></span>
		BaseDao<span class="token punctuation">.</span><span class="token function">closeResource</span><span class="token punctuation">(</span>connection<span class="token punctuation">,</span> null<span class="token punctuation">,</span> null<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	<span class="token keyword">return</span> user<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token comment">/*@Test
public void test() {
	UserServiceImpl userService = new UserServiceImpl();
	String userCode = "admin";
	String userPassword = "12345678";
	User admin = userService.login(userCode, userPassword);
	System.out.println(admin.getUserPassword());

}
*/</span>

}

编写Servlet

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import pojo.User;
import util.Constants;
import service.user.UserService;
import service.user.UserServiceImpl;

@SuppressWarnings(“serial”)
public class LoginServlet extends HttpServlet{
//接受用户参数、调用业务层、转发视图
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// TODO 自动生成的方法存根

	System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"login ============ "</span> <span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token comment">//获取用户名和密码</span>
	String userCode <span class="token operator">=</span> req<span class="token punctuation">.</span><span class="token function">getParameter</span><span class="token punctuation">(</span><span class="token string">"userCode"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	String userPassword <span class="token operator">=</span> req<span class="token punctuation">.</span><span class="token function">getParameter</span><span class="token punctuation">(</span><span class="token string">"userPassword"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token comment">//调用service方法，进行用户匹配</span>
	UserService userService <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">UserServiceImpl</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	User user <span class="token operator">=</span> userService<span class="token punctuation">.</span><span class="token function">login</span><span class="token punctuation">(</span>userCode<span class="token punctuation">,</span>userPassword<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">if</span><span class="token punctuation">(</span>null <span class="token operator">!=</span> user<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span><span class="token comment">//登录成功</span>
		<span class="token comment">//放入session</span>
		req<span class="token punctuation">.</span><span class="token function">getSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span>Constants<span class="token punctuation">.</span>USER_SESSION<span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token comment">//页面跳转（frame.jsp）</span>
		resp<span class="token punctuation">.</span><span class="token function">sendRedirect</span><span class="token punctuation">(</span><span class="token string">"jsp/frame.jsp"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span><span class="token keyword">else</span><span class="token punctuation">{<!-- --></span>
		<span class="token comment">//页面跳转（login.jsp）带出提示信息--转发</span>
		req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"error"</span><span class="token punctuation">,</span> <span class="token string">"用户名或密码不正确"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		req<span class="token punctuation">.</span><span class="token function">getRequestDispatcher</span><span class="token punctuation">(</span><span class="token string">"login.jsp"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">forward</span><span class="token punctuation">(</span>req<span class="token punctuation">,</span>resp<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
<span class="token punctuation">}</span>
<span class="token annotation punctuation">@Override</span>
<span class="token keyword">protected</span> <span class="token keyword">void</span> <span class="token function">doPost</span><span class="token punctuation">(</span>HttpServletRequest req<span class="token punctuation">,</span> HttpServletResponse resp<span class="token punctuation">)</span> <span class="token keyword">throws</span> ServletException<span class="token punctuation">,</span> IOException <span class="token punctuation">{<!-- --></span>
	<span class="token comment">// TODO 自动生成的方法存根</span>
	<span class="token function">doGet</span><span class="token punctuation">(</span>req<span class="token punctuation">,</span> resp<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

注册Servlet

<servlet>
	<servlet-name>LoginServlet</servlet-name>
	<servlet-class>com.kuang.servlet.user.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
	<servlet-name>LoginServlet</servlet-name>
	<url-pattern>/login.do</url-pattern>
</servlet-mapping>

 
  
  
 
  
  
   
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测试访问,保证以上功能可以成功

登录功能优化

注销功能
思路：移除session，返回登录页面

public class LogoutServlet extends HttpServlet {
    
    
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">doPOST</span><span class="token punctuation">(</span>HttpServletRequest request<span class="token punctuation">,</span> HttpServletResponse response<span class="token punctuation">)</span>
		<span class="token keyword">throws</span> ServletException<span class="token punctuation">,</span> IOException <span class="token punctuation">{<!-- --></span>
	<span class="token function">doGet</span><span class="token punctuation">(</span>request<span class="token punctuation">,</span> response<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">doGet</span><span class="token punctuation">(</span>HttpServletRequest request<span class="token punctuation">,</span> HttpServletResponse response<span class="token punctuation">)</span>
		<span class="token keyword">throws</span> ServletException<span class="token punctuation">,</span> IOException <span class="token punctuation">{<!-- --></span>
	<span class="token comment">//清除session</span>
	request<span class="token punctuation">.</span><span class="token function">getSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">removeAttribute</span><span class="token punctuation">(</span>Constants<span class="token punctuation">.</span>USER_SESSION<span class="token punctuation">)</span><span class="token punctuation">;</span>
	response<span class="token punctuation">.</span><span class="token function">sendRedirect</span><span class="token punctuation">(</span>request<span class="token punctuation">.</span><span class="token function">getContextPath</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">+</span><span class="token string">"/login.jsp"</span><span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token comment">//返回登录页面</span>
<span class="token punctuation">}</span>

}

注册xml

<servlet>
	<servlet-name>LogoutServlet</servlet-name>
	<servlet-class>servlet.user.LogoutServlet</servlet-class>
</servlet>
<servlet-mapping>
	<servlet-name>LogoutServlet</servlet-name>
	<url-pattern>/jsp/logout.do</url-pattern>
</servlet-mapping>

 
  
  
 
  
  
   
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登录拦截优化

编写一个过滤器，并注册

import java.io.IOException;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import pojo.User;
import util.Constants;

public class SysFilter implements Filter{
public void init(FilterConfig filterConfig) throws ServletException{

<span class="token punctuation">}</span>

<span class="token annotation punctuation">@Override</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">doFilter</span><span class="token punctuation">(</span>ServletRequest req<span class="token punctuation">,</span> ServletResponse resp<span class="token punctuation">,</span> FilterChain chain<span class="token punctuation">)</span>
		<span class="token keyword">throws</span> IOException<span class="token punctuation">,</span> ServletException <span class="token punctuation">{<!-- --></span>
	<span class="token comment">// TODO 自动生成的方法存根</span>
	HttpServletRequest request <span class="token operator">=</span>  <span class="token punctuation">(</span>HttpServletRequest<span class="token punctuation">)</span>req<span class="token punctuation">;</span>
	HttpServletResponse response <span class="token operator">=</span> <span class="token punctuation">(</span>HttpServletResponse<span class="token punctuation">)</span>resp<span class="token punctuation">;</span>
	
	<span class="token comment">//过滤器，从session中获取用户</span>
	User user <span class="token operator">=</span> <span class="token punctuation">(</span>User<span class="token punctuation">)</span>request<span class="token punctuation">.</span><span class="token function">getSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getAttribute</span><span class="token punctuation">(</span>Constants<span class="token punctuation">.</span>USER_SESSION<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">if</span><span class="token punctuation">(</span>user <span class="token operator">==</span> null<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span><span class="token comment">//已经被移除或者注销了，或者未登录</span>
		response<span class="token punctuation">.</span><span class="token function">sendRedirect</span><span class="token punctuation">(</span><span class="token string">"/smbms/error.jsp"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span><span class="token keyword">else</span> <span class="token punctuation">{<!-- --></span>
		chain<span class="token punctuation">.</span><span class="token function">doFilter</span><span class="token punctuation">(</span>req<span class="token punctuation">,</span> resp<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
<span class="token punctuation">}</span>

<span class="token annotation punctuation">@Override</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">destroy</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
	<span class="token comment">// TODO 自动生成的方法存根</span>
	
<span class="token punctuation">}</span>

}

注册xml

<!-- 用户登录过滤器 -->
<filter>
	<filter-name>SysFilter</filter-name>
	<filter-class>filter.SysFilter</filter-class>
</filter> 
<filter-mapping>
	<filter-name>SysFilter</filter-name>
	<url-pattern>/jsp/*</url-pattern>
</filter-mapping>

 
  
  
 
  
  
   
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测试，登录，注销，权限，都要保证OK

密码修改

导入前端素材

<li><a href="${pageContext.request.contextPath }/jsp/pwdmodify.jsp">密码修改</a></li>

写项目，建议从底层向上写
UserDao接口

//修改当前用户密码
	public int updatePwd(Connection connection,int id,int password)throws SQLException, Exception;

 
  
  
 
  
  
   
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UserDao接口实现类

@Override//修改当前密码
	public int updatePwd(Connection connection, int id, int password) throws Exception {
    
    
		// TODO 自动生成的方法存根
		PreparedStatement pstm = null;
		int execute =0;
		if(connection!=null) {
    
    
			String sql = "update smbms_user set = userPassword = ? where id = ?";
			Object[] params = {
    
    password,id};
			execute = BaseDao.execute(connection, pstm, sql, params);
			BaseDao.closeResource(null, pstm, null);
		}
		return execute;			
	}

 
  
  
 
  
  
   
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UserService层

public boolean updatePwd(int id,int password)throws SQLException, Exception;

 
  
  
 
  
  
   
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UserService实现类

public boolean updatePwd(int id, int password) throws SQLException, Exception {
    
    
		// TODO 自动生成的方法存根
		Connection connection = null;
		boolean flag = false;
		//修改密码
		try {
    
    
			connection = BaseDao.getConnection();
			if(userDao.updatePwd(connection, id, password)>0) {
    
    
				flag = true;
			}
		} catch (SQLException e) {
    
    
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		} finally {
    
    
			BaseDao.closeResource(connection, null, null);
	<span class="token punctuation">}</span>
	<span class="token keyword">return</span> flag<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

servlet记得实现复用，要提取出方法！
在 dao层 和 service层 自己写映射类和实现类
下面是 servlet层 的主体

public class UserServlet extends HttpServlet {
    
    
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
		// TODO 自动生成的方法存根
		String method = req.getParameter("method");
		if (method != "savepwd" && method != null) {
    
    
			this.updatePwd(req, resp);
		}
		//实现复用~~~~~~
		// 想添加新的增删改查，直接用if(method != "savepwd" && method != null);
	}
<span class="token annotation punctuation">@Override</span>
<span class="token keyword">protected</span> <span class="token keyword">void</span> <span class="token function">doPost</span><span class="token punctuation">(</span>HttpServletRequest req<span class="token punctuation">,</span> HttpServletResponse resp<span class="token punctuation">)</span> <span class="token keyword">throws</span> ServletException<span class="token punctuation">,</span> IOException <span class="token punctuation">{<!-- --></span>
	<span class="token comment">// TODO 自动生成的方法存根</span>
	<span class="token function">doGet</span><span class="token punctuation">(</span>req<span class="token punctuation">,</span> resp<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">updatePwd</span><span class="token punctuation">(</span>HttpServletRequest req<span class="token punctuation">,</span> HttpServletResponse resp<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
	<span class="token comment">// 通过session获得用户id</span>
	Object o <span class="token operator">=</span> req<span class="token punctuation">.</span><span class="token function">getSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getAttribute</span><span class="token punctuation">(</span>Constants<span class="token punctuation">.</span>USER_SESSION<span class="token punctuation">)</span><span class="token punctuation">;</span>
	String newpassword <span class="token operator">=</span> req<span class="token punctuation">.</span><span class="token function">getParameter</span><span class="token punctuation">(</span><span class="token string">"newpassword"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">boolean</span> flag <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span>
	<span class="token keyword">if</span> <span class="token punctuation">(</span>o <span class="token operator">!=</span> null <span class="token operator">&amp;&amp;</span> newpassword <span class="token operator">!=</span> null<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		UserService userService <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">UserServiceImpl</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

		<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
			flag <span class="token operator">=</span> userService<span class="token punctuation">.</span><span class="token function">updatePwd</span><span class="token punctuation">(</span><span class="token punctuation">(</span><span class="token punctuation">(</span>User<span class="token punctuation">)</span> o<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getId</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> newpassword<span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">SQLException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
			<span class="token comment">// TODO 自动生成的 catch 块</span>
			e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">Exception</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
			<span class="token comment">// TODO 自动生成的 catch 块</span>
			e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>
		<span class="token keyword">if</span> <span class="token punctuation">(</span>flag<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
			req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"message"</span><span class="token punctuation">,</span> <span class="token string">"密码修改成功，请退出，使用新密码登录"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			<span class="token comment">// 密码修改成功,移除session(移除后不能再次修改密码,建议不移除)</span>
			req<span class="token punctuation">.</span><span class="token function">getSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">removeAttribute</span><span class="token punctuation">(</span>Constants<span class="token punctuation">.</span>USER_SESSION<span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{<!-- --></span>
			<span class="token comment">// 密码修改失败</span>
			req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"message"</span><span class="token punctuation">,</span> <span class="token string">"密码修改失败"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>

	<span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{<!-- --></span>
		<span class="token comment">// 密码修改有问题</span>
		req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"message"</span><span class="token punctuation">,</span> <span class="token string">"新密码有问题"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
		req<span class="token punctuation">.</span><span class="token function">getRequestDispatcher</span><span class="token punctuation">(</span><span class="token string">"/jsp/pwdmodify.jsp"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">forward</span><span class="token punctuation">(</span>req<span class="token punctuation">,</span> resp<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">ServletException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		<span class="token comment">// TODO 自动生成的 catch 块</span>
		e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">IOException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		<span class="token comment">// TODO 自动生成的 catch 块</span>
		e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
<span class="token punctuation">}</span>

}

注册xml

<servlet>
		<servlet-name>UserServlet</servlet-name>
		<servlet-class>servlet.user.UserServlet</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>UserServlet</servlet-name>
		<url-pattern>/jsp/user.do</url-pattern>
	</servlet-mapping>

 
  
  
 
  
  
   
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测试

优化密码修改使用Ajax

阿里巴巴的fastjson

<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.68</version>
</dependency>

 
  
  
 
  
  
   
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后台代码修改

导入阿里的包

<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.68</version>
</dependency>

 
  
  
 
  
  
   
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import java.io.IOException;
import java.io.PrintWriter;
//import java.io.Writer;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.mysql.cj.util.StringUtils;
import com.mysql.cj.xdevapi.JsonArray;

//import com.mysql.cj.util.StringUtils;

import pojo.User;
import service.user.UserService;
import service.user.UserServiceImpl;
import util.Constants;

@SuppressWarnings(“serial”)
public class UserServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// TODO 自动生成的方法存根
String method = req.getParameter(“method”);
if (method.equals( “savepwd”) && method != null) {
this.updatePwd(req, resp);
}else if (method.equals( “pwdmodify”) && method != null) {

	<span class="token punctuation">}</span>
	<span class="token comment">// 想添加新的增删改查，直接用if(method != "savepwd" &amp;&amp; method != null);</span>
<span class="token punctuation">}</span>

<span class="token annotation punctuation">@Override</span>
<span class="token keyword">protected</span> <span class="token keyword">void</span> <span class="token function">doPost</span><span class="token punctuation">(</span>HttpServletRequest req<span class="token punctuation">,</span> HttpServletResponse resp<span class="token punctuation">)</span> <span class="token keyword">throws</span> ServletException<span class="token punctuation">,</span> IOException <span class="token punctuation">{<!-- --></span>
	<span class="token comment">// TODO 自动生成的方法存根</span>
	<span class="token function">doGet</span><span class="token punctuation">(</span>req<span class="token punctuation">,</span> resp<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">updatePwd</span><span class="token punctuation">(</span>HttpServletRequest req<span class="token punctuation">,</span> HttpServletResponse resp<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
	<span class="token comment">// 通过session获得用户id</span>
	Object o <span class="token operator">=</span> req<span class="token punctuation">.</span><span class="token function">getSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getAttribute</span><span class="token punctuation">(</span>Constants<span class="token punctuation">.</span>USER_SESSION<span class="token punctuation">)</span><span class="token punctuation">;</span>
	String newpassword <span class="token operator">=</span> req<span class="token punctuation">.</span><span class="token function">getParameter</span><span class="token punctuation">(</span><span class="token string">"newpassword"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">boolean</span> flag <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span>
	<span class="token keyword">if</span> <span class="token punctuation">(</span>o <span class="token operator">!=</span> null <span class="token operator">&amp;&amp;</span> newpassword <span class="token operator">!=</span> null<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		UserService userService <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">UserServiceImpl</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

		<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
			flag <span class="token operator">=</span> userService<span class="token punctuation">.</span><span class="token function">updatePwd</span><span class="token punctuation">(</span><span class="token punctuation">(</span><span class="token punctuation">(</span>User<span class="token punctuation">)</span> o<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getId</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> newpassword<span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">SQLException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
			<span class="token comment">// TODO 自动生成的 catch 块</span>
			e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">Exception</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
			<span class="token comment">// TODO 自动生成的 catch 块</span>
			e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>
		<span class="token keyword">if</span> <span class="token punctuation">(</span>flag<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
			req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"message"</span><span class="token punctuation">,</span> <span class="token string">"密码修改成功，请退出，使用新密码登录"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			<span class="token comment">// 密码修改成功,移除session(移除后不能再次修改密码,建议不移除)</span>
			req<span class="token punctuation">.</span><span class="token function">getSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">removeAttribute</span><span class="token punctuation">(</span>Constants<span class="token punctuation">.</span>USER_SESSION<span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{<!-- --></span>
			<span class="token comment">// 密码修改失败</span>
			req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"message"</span><span class="token punctuation">,</span> <span class="token string">"密码修改失败"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>

	<span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{<!-- --></span>
		<span class="token comment">// 密码修改有问题</span>
		req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"message"</span><span class="token punctuation">,</span> <span class="token string">"新密码有问题"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
		req<span class="token punctuation">.</span><span class="token function">getRequestDispatcher</span><span class="token punctuation">(</span><span class="token string">"/jsp/pwdmodify.jsp"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">forward</span><span class="token punctuation">(</span>req<span class="token punctuation">,</span> resp<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">ServletException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		<span class="token comment">// TODO 自动生成的 catch 块</span>
		e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">IOException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		<span class="token comment">// TODO 自动生成的 catch 块</span>
		e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">pqdmodify</span><span class="token punctuation">(</span>HttpServletRequest req<span class="token punctuation">,</span> HttpServletResponse resp<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
	<span class="token comment">// 通过session获得用户id</span>
	Object o <span class="token operator">=</span> req<span class="token punctuation">.</span><span class="token function">getSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getAttribute</span><span class="token punctuation">(</span>Constants<span class="token punctuation">.</span>USER_SESSION<span class="token punctuation">)</span><span class="token punctuation">;</span>
	String oldpassword <span class="token operator">=</span> req<span class="token punctuation">.</span><span class="token function">getParameter</span><span class="token punctuation">(</span><span class="token string">"oldpassword"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	
	Map<span class="token generics function"><span class="token punctuation">&lt;</span>String<span class="token punctuation">,</span> String<span class="token punctuation">&gt;</span></span> resultMap <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">HashMap</span><span class="token generics function"><span class="token punctuation">&lt;</span>String<span class="token punctuation">,</span> String<span class="token punctuation">&gt;</span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">if</span><span class="token punctuation">(</span>o<span class="token operator">==</span>null<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span><span class="token comment">//session失效，session过期了</span>
		resultMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"result"</span><span class="token punctuation">,</span><span class="token string">"seesionerror"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span><span class="token keyword">else</span> <span class="token keyword">if</span><span class="token punctuation">(</span>StringUtils<span class="token punctuation">.</span><span class="token function">isNullOrEmpty</span><span class="token punctuation">(</span>oldpassword<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span><span class="token comment">//输入密码为空</span>
		resultMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"result"</span><span class="token punctuation">,</span><span class="token string">"error"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span><span class="token keyword">else</span> <span class="token punctuation">{<!-- --></span><span class="token comment">//</span>
		String userPassword <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token punctuation">(</span>User<span class="token punctuation">)</span>o<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getUserPassword</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token comment">//seesion中的用户密码</span>
		<span class="token keyword">if</span><span class="token punctuation">(</span>oldpassword<span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span>userPassword<span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
			resultMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"result"</span><span class="token punctuation">,</span><span class="token string">"true"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span><span class="token keyword">else</span> <span class="token punctuation">{<!-- --></span>
			resultMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"result"</span><span class="token punctuation">,</span><span class="token string">"false"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>
	<span class="token punctuation">}</span>
	
	
	<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
		resp<span class="token punctuation">.</span><span class="token function">setContentType</span><span class="token punctuation">(</span><span class="token string">"application/josn"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		PrintWriter writer <span class="token operator">=</span> resp<span class="token punctuation">.</span><span class="token function">getWriter</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token comment">/*
		 * resultMap = ["result","sessionerror","result",error]
		 * josn格式={key,value
		 */</span>
		<span class="token comment">//writer.write(JSONArray.toJSONString(resultMap));</span>
		writer<span class="token punctuation">.</span><span class="token function">write</span><span class="token punctuation">(</span>JsonArray<span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		writer<span class="token punctuation">.</span><span class="token function">flush</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		writer<span class="token punctuation">.</span><span class="token function">close</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">IOException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		<span class="token comment">// TODO 自动生成的 catch 块</span>
		e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
<span class="token punctuation">}</span>

}

测试

用户管理实现

在这里插入图片描述

导入分页的工具类-PageSupport
用户列表页面导入-userlist.jsp

1、获取用户数量

UserDao

//根据用户名或者角色查询用户总数
public int getUserCount(Connection connection,String username ,int userRole)throws SQLException, Exception;

 
  
  
 
  
  
   
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UserDaoImpl

@Override
	public int getUserCount(Connection connection, String userName, int userRole)
			throws Exception {
    
    
		// TODO Auto-generated method stub
		PreparedStatement pstm = null;
		ResultSet rs = null;
		int count = 0;
		if(connection != null){
    
    
			StringBuffer sql = new StringBuffer();
			sql.append("select count(1) as count from smbms_user u,smbms_role r where u.userRole = r.id");
			List<Object> list = new ArrayList<Object>();
			if(!StringUtils.isNullOrEmpty(userName)){
    
    
				sql.append(" and u.userName like ?");
				list.add("%"+userName+"%");
			}
			if(userRole > 0){
    
    
				sql.append(" and u.userRole = ?");
				list.add(userRole);
			}
			Object[] params = list.toArray();
			System.out.println("sql ----> " + sql.toString());
			rs = BaseDao.execute(connection, pstm, rs, sql.toString(), params);
			if(rs.next()){
    
    
				count = rs.getInt("count");
			}
			BaseDao.closeResource(null, pstm, rs);
		}
		return count;
	}

 
  
  
 
  
  
   
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UserService

//查询记录数
	public int getUserCount(String username, int userRole);

 
  
  
 
  
  
   
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UserServiceImpl

//查询记录数
	@Override
	public int getUserCount(String queryUserName, int queryUserRole) {
    
    
		// TODO Auto-generated method stub
		Connection connection = null;
		int count = 0;
		System.out.println("queryUserName ---- > " + queryUserName);
		System.out.println("queryUserRole ---- > " + queryUserRole);
		try {
    
    
			connection = BaseDao.getConnection();
			count = userDao.getUserCount(connection, queryUserName,queryUserRole);
		} catch (Exception e) {
    
    
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
    
    
			BaseDao.closeResource(connection, null, null);
		}
		//System.out.println("count"+count);
		return count;
	}

 
  
  
 
  
  
   
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2、获取用户列表

1.UserDao

//通过条件查询-userList
	public List<User> getUserList(Connection connection, String userName, int userRole, int currentPageNo, int pageSize)throws Exception;

 
  
  
 
  
  
   
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UserDaoImpl

@Override
	public List<User> getUserList(Connection connection, String userName,int userRole,int currentPageNo, int pageSize)
			throws Exception {
    
    
		// TODO Auto-generated method stub
		PreparedStatement pstm = null;
		ResultSet rs = null;
		List<User> userList = new ArrayList<User>();
		if(connection != null){
    
    
			StringBuffer sql = new StringBuffer();
			sql.append("select u.*,r.roleName as userRoleName from smbms_user u,smbms_role r where u.userRole = r.id");
			List<Object> list = new ArrayList<Object>();
			if(!StringUtils.isNullOrEmpty(userName)){
    
    
				sql.append(" and u.userName like ?");
				list.add("%"+userName+"%");
			}
			if(userRole > 0){
    
    
				sql.append(" and u.userRole = ?");
				list.add(userRole);
			}
			//在数据库中，分页显示 limit startIndex，pageSize；总数
			//当前页  (当前页-1)*页面大小
			//0,5	1,0	 01234
			//5,5	5,0	 56789
			//10,5	10,0 10~
			sql.append(" order by creationDate DESC limit ?,?");
			currentPageNo = (currentPageNo-1)*pageSize;
			list.add(currentPageNo);
			list.add(pageSize);
		Object<span class="token punctuation">[</span><span class="token punctuation">]</span> params <span class="token operator">=</span> list<span class="token punctuation">.</span><span class="token function">toArray</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"sql ----&gt; "</span> <span class="token operator">+</span> sql<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		
		rs <span class="token operator">=</span> BaseDao<span class="token punctuation">.</span><span class="token function">execute</span><span class="token punctuation">(</span>connection<span class="token punctuation">,</span> pstm<span class="token punctuation">,</span> rs<span class="token punctuation">,</span> sql<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> params<span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token keyword">while</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">next</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
			User _user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			_user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">getInt</span><span class="token punctuation">(</span><span class="token string">"id"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			_user<span class="token punctuation">.</span><span class="token function">setUserCode</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">getString</span><span class="token punctuation">(</span><span class="token string">"userCode"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			_user<span class="token punctuation">.</span><span class="token function">setUserName</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">getString</span><span class="token punctuation">(</span><span class="token string">"userName"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			_user<span class="token punctuation">.</span><span class="token function">setGender</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">getInt</span><span class="token punctuation">(</span><span class="token string">"gender"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			_user<span class="token punctuation">.</span><span class="token function">setBirthday</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">getDate</span><span class="token punctuation">(</span><span class="token string">"birthday"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			_user<span class="token punctuation">.</span><span class="token function">setPhone</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">getString</span><span class="token punctuation">(</span><span class="token string">"phone"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			_user<span class="token punctuation">.</span><span class="token function">setUserRole</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">getInt</span><span class="token punctuation">(</span><span class="token string">"userRole"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			_user<span class="token punctuation">.</span><span class="token function">setUserRoleName</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">getString</span><span class="token punctuation">(</span><span class="token string">"userRoleName"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			userList<span class="token punctuation">.</span><span class="token function">add</span><span class="token punctuation">(</span>_user<span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>
		BaseDao<span class="token punctuation">.</span><span class="token function">closeResource</span><span class="token punctuation">(</span>null<span class="token punctuation">,</span> pstm<span class="token punctuation">,</span> rs<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	<span class="token keyword">return</span> userList<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

UserService

//根据条件查询用户列表
	public List<User> getUserList(String queryUserName, int queryUserRole, int currentPageNo, int pageSize);

 
  
  
 
  
  
   
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UserServiceImpl

@Override
	public List<User> getUserList(String queryUserName,int queryUserRole,int currentPageNo, int pageSize) {
    
    
		// TODO Auto-generated method stub
		Connection connection = null;
		List<User> userList = null;
		System.out.println("queryUserName ---- > " + queryUserName);
		System.out.println("queryUserRole ---- > " + queryUserRole);
		System.out.println("currentPageNo ---- > " + currentPageNo);
		System.out.println("pageSize ---- > " + pageSize);
		try {
    
    
			connection = BaseDao.getConnection();
			userList = userDao.getUserList(connection, queryUserName,queryUserRole,currentPageNo,pageSize);
		} catch (Exception e) {
    
    
			// TODO Auto-generated catch block 
			e.printStackTrace();
		}finally{
    
    
			BaseDao.closeResource(connection, null, null);
		}
		return userList;
	}

 
  
  
 
  
  
   
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3、获取角色操作

为了我们的职责统一，我们可以把角色的操作单独放在一个包中，和pojo类对应。。。

RoleDao

//获取角色列表
		public List<Role> getRoleList(Connection connection)throws Exception;

 
  
  
 
  
  
   
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RoleDaoIpml

public class RoleDaoImpl implements RoleDao {
    
    
<span class="token annotation punctuation">@Override</span>
<span class="token keyword">public</span> List<span class="token generics function"><span class="token punctuation">&lt;</span>Role<span class="token punctuation">&gt;</span></span> <span class="token function">getRoleList</span><span class="token punctuation">(</span>Connection connection<span class="token punctuation">)</span> <span class="token keyword">throws</span> Exception <span class="token punctuation">{<!-- --></span>
	PreparedStatement pstm <span class="token operator">=</span> null<span class="token punctuation">;</span>
	ResultSet rs <span class="token operator">=</span> null<span class="token punctuation">;</span>
	List<span class="token generics function"><span class="token punctuation">&lt;</span>Role<span class="token punctuation">&gt;</span></span> roleList <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ArrayList</span><span class="token generics function"><span class="token punctuation">&lt;</span>Role<span class="token punctuation">&gt;</span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">if</span> <span class="token punctuation">(</span>connection <span class="token operator">!=</span> null<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		String sql <span class="token operator">=</span> <span class="token string">"select * from smbms_role"</span><span class="token punctuation">;</span>
		Object<span class="token punctuation">[</span><span class="token punctuation">]</span> params <span class="token operator">=</span> <span class="token punctuation">{<!-- --></span><span class="token punctuation">}</span><span class="token punctuation">;</span>
		rs <span class="token operator">=</span> BaseDao<span class="token punctuation">.</span><span class="token function">execute</span><span class="token punctuation">(</span>connection<span class="token punctuation">,</span> pstm<span class="token punctuation">,</span> rs<span class="token punctuation">,</span> sql<span class="token punctuation">,</span> params<span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token keyword">while</span> <span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">next</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
			Role _role <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Role</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			_role<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">getInt</span><span class="token punctuation">(</span><span class="token string">"id"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			_role<span class="token punctuation">.</span><span class="token function">setRoleCode</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">getString</span><span class="token punctuation">(</span><span class="token string">"roleCode"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			_role<span class="token punctuation">.</span><span class="token function">setRoleName</span><span class="token punctuation">(</span>rs<span class="token punctuation">.</span><span class="token function">getString</span><span class="token punctuation">(</span><span class="token string">"roleName"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
			roleList<span class="token punctuation">.</span><span class="token function">add</span><span class="token punctuation">(</span>_role<span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>
		BaseDao<span class="token punctuation">.</span><span class="token function">closeResource</span><span class="token punctuation">(</span>null<span class="token punctuation">,</span> pstm<span class="token punctuation">,</span> rs<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>

	<span class="token keyword">return</span> roleList<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

RoleService

public interface RoleService {
    
    
	//角色列表查询
	public List<Role> getRoleList();

}

RoleServiceIpml

public class RoleServiceImpl implements RoleService{
    
    
<span class="token keyword">private</span> RoleDao roleDao<span class="token punctuation">;</span>

<span class="token keyword">public</span> <span class="token function">RoleServiceImpl</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
	roleDao <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">RoleDaoImpl</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token annotation punctuation">@Override</span>
<span class="token keyword">public</span> List<span class="token generics function"><span class="token punctuation">&lt;</span>Role<span class="token punctuation">&gt;</span></span> <span class="token function">getRoleList</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
	Connection connection <span class="token operator">=</span> null<span class="token punctuation">;</span>
	List<span class="token generics function"><span class="token punctuation">&lt;</span>Role<span class="token punctuation">&gt;</span></span> roleList <span class="token operator">=</span> null<span class="token punctuation">;</span>
	<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
		connection <span class="token operator">=</span> BaseDao<span class="token punctuation">.</span><span class="token function">getConnection</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		roleList <span class="token operator">=</span> roleDao<span class="token punctuation">.</span><span class="token function">getRoleList</span><span class="token punctuation">(</span>connection<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">Exception</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span><span class="token keyword">finally</span><span class="token punctuation">{<!-- --></span>
		BaseDao<span class="token punctuation">.</span><span class="token function">closeResource</span><span class="token punctuation">(</span>connection<span class="token punctuation">,</span> null<span class="token punctuation">,</span> null<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	<span class="token keyword">return</span> roleList<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

4、用户显示的Servlet

获取用户前端的数据（查询）
判断请求是否需要执行，看参数的值判断
为了实现分页，需要计算出当前页面和总页面，页面大小…
用户列表展示
返回前端

//重点、难点
	private void query(HttpServletRequest req, HttpServletResponse resp) {
    
    
		// TODO 自动生成的方法存根
		//查询用户列表
		//从前端获取数据
		//查询用户列表
		String queryUserName = req.getParameter("queryname");
		String temp = req.getParameter("queryUserRole");
		String pageIndex = req.getParameter("pageIndex");
		int queryUserRole = 0;
	<span class="token comment">//获取用户列表</span>
	UserServiceImpl userService <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">UserServiceImpl</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	List<span class="token generics function"><span class="token punctuation">&lt;</span>User<span class="token punctuation">&gt;</span></span> userList <span class="token operator">=</span> null<span class="token punctuation">;</span>
	
	<span class="token comment">//第一此请求肯定是走第一页，页面大小固定的</span>
	<span class="token comment">//设置页面容量</span>
	<span class="token keyword">int</span> pageSize <span class="token operator">=</span> <span class="token number">5</span><span class="token punctuation">;</span><span class="token comment">//把它设置在配置文件里,后面方便修改</span>
	<span class="token comment">//当前页码</span>
	<span class="token keyword">int</span> currentPageNo <span class="token operator">=</span> <span class="token number">1</span><span class="token punctuation">;</span>
	
	<span class="token keyword">if</span><span class="token punctuation">(</span>queryUserName <span class="token operator">==</span> null<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
		queryUserName <span class="token operator">=</span> <span class="token string">""</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	<span class="token keyword">if</span><span class="token punctuation">(</span>temp <span class="token operator">!=</span> null <span class="token operator">&amp;&amp;</span> <span class="token operator">!</span>temp<span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span><span class="token string">""</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
		queryUserRole <span class="token operator">=</span> Integer<span class="token punctuation">.</span><span class="token function">parseInt</span><span class="token punctuation">(</span>temp<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	<span class="token keyword">if</span><span class="token punctuation">(</span>pageIndex <span class="token operator">!=</span> null<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		currentPageNo <span class="token operator">=</span> Integer<span class="token punctuation">.</span><span class="token function">parseInt</span><span class="token punctuation">(</span>pageIndex<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	<span class="token comment">//获取用户总数（分页	上一页：下一页的情况）</span>
	<span class="token comment">//总数量（表）	</span>
	<span class="token keyword">int</span> totalCount	<span class="token operator">=</span> userService<span class="token punctuation">.</span><span class="token function">getUserCount</span><span class="token punctuation">(</span>queryUserName<span class="token punctuation">,</span>queryUserRole<span class="token punctuation">)</span><span class="token punctuation">;</span>
		
	<span class="token comment">//总页数支持</span>
	PageSupport pageSupport <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">PageSupport</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	pageSupport<span class="token punctuation">.</span><span class="token function">setCurrentPageNo</span><span class="token punctuation">(</span>currentPageNo<span class="token punctuation">)</span><span class="token punctuation">;</span>
	pageSupport<span class="token punctuation">.</span><span class="token function">setPageSize</span><span class="token punctuation">(</span>pageSize<span class="token punctuation">)</span><span class="token punctuation">;</span>
	pageSupport<span class="token punctuation">.</span><span class="token function">setTotalCount</span><span class="token punctuation">(</span>totalCount<span class="token punctuation">)</span><span class="token punctuation">;</span>
	
	<span class="token keyword">int</span> totalPageCount <span class="token operator">=</span>pageSupport<span class="token punctuation">.</span><span class="token function">getTotalPageCount</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token comment">//总共有几页</span>
	<span class="token comment">//(totalCount+pageSize-1/pageSize)取整</span>
	<span class="token comment">// pageSupport.getTotalCount()</span>
	
	<span class="token comment">//System.out.println("totalCount ="+totalCount);</span>
	<span class="token comment">//System.out.println("pageSize ="+pageSize);</span>
	<span class="token comment">//System.out.println("totalPageCount ="+totalPageCount);</span>
	<span class="token comment">//控制首页和尾页</span>
	<span class="token comment">//如果页面小于 1 就显示第一页的东西</span>
	<span class="token keyword">if</span><span class="token punctuation">(</span>currentPageNo <span class="token operator">&lt;</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		currentPageNo <span class="token operator">=</span> <span class="token number">1</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span><span class="token keyword">else</span> <span class="token keyword">if</span><span class="token punctuation">(</span>currentPageNo <span class="token operator">&gt;</span> totalPageCount<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span><span class="token comment">//如果页面大于了最后一页就显示最后一页</span>
		currentPageNo <span class="token operator">=</span>totalPageCount<span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	
	userList <span class="token operator">=</span> userService<span class="token punctuation">.</span><span class="token function">getUserList</span><span class="token punctuation">(</span>queryUserName<span class="token punctuation">,</span> queryUserRole<span class="token punctuation">,</span> currentPageNo<span class="token punctuation">,</span> pageSize<span class="token punctuation">)</span><span class="token punctuation">;</span>
	req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"userList"</span><span class="token punctuation">,</span> userList<span class="token punctuation">)</span><span class="token punctuation">;</span>
	
	RoleServiceImpl roleService <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">RoleServiceImpl</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	List<span class="token generics function"><span class="token punctuation">&lt;</span>Role<span class="token punctuation">&gt;</span></span> roleList <span class="token operator">=</span> roleService<span class="token punctuation">.</span><span class="token function">getRoleList</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"roleList"</span><span class="token punctuation">,</span> roleList<span class="token punctuation">)</span><span class="token punctuation">;</span>
	req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"totalCount"</span><span class="token punctuation">,</span> totalCount<span class="token punctuation">)</span><span class="token punctuation">;</span> 
	req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"currentPageNo"</span><span class="token punctuation">,</span> currentPageNo<span class="token punctuation">)</span><span class="token punctuation">;</span>
	req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"totalPageCount"</span><span class="token punctuation">,</span> totalPageCount<span class="token punctuation">)</span><span class="token punctuation">;</span>
	req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"queryUserName"</span><span class="token punctuation">,</span> queryUserName<span class="token punctuation">)</span><span class="token punctuation">;</span>
	req<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"queryUserRole"</span><span class="token punctuation">,</span> queryUserRole<span class="token punctuation">)</span><span class="token punctuation">;</span>
	
	<span class="token comment">//返回前端</span>
	<span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>
		req<span class="token punctuation">.</span><span class="token function">getRequestDispatcher</span><span class="token punctuation">(</span><span class="token string">"userlist.jsp"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">forward</span><span class="token punctuation">(</span>req<span class="token punctuation">,</span> resp<span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">ServletException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		<span class="token comment">// TODO 自动生成的 catch 块</span>
		e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">IOException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
		<span class="token comment">// TODO 自动生成的 catch 块</span>
		e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>

<span class="token punctuation">}</span>

小黄鸭调试法：自言自语

项目原理流程图：

剩下的手打一遍，然后各种打错排查，，，
虽然不建议，但还是直接导入文件算了，粘贴复制也行0-0（前提是自己先码一遍）

源码在最后

SMBMS项目源码链接：
Eclipse版（个人手打版，已排错，可运行）
https://www.lanzoux.com/iGLJTdusuyf

6月20号，补上了之前漏掉的smbms的MySQL数据库（链接已更新）

IDEA版（狂神原版）- 进群拿–>狂神说Java交流群：1063621833

想学习 Docker 技术的下边请
【狂神说Java】Docker最新超详细版教程通俗易懂
https://www.bilibili.com/video/BV1og4y1q7M4

源码在最后

文章目录

- SMBMS(超市管理项目)

SMBMS(超市管理项目)

在这里插入图片描述

数据库：
在这里插入图片描述
项目如何搭建？
考虑是不是用maven？ jar包，依赖

搭建项目准备工作

搭建一个maven web 项目
配置Tomcat
测试项目是否能够跑起来
导入项目中需要的jar包;
jsp，Servlet，mysql驱动jstl，stand…
构建项目包结构
编写实体类
ROM映射:表-类映射

编写基础公共类
1、数据库配置文件（mysql5.xx和8.xx的编写有差异）

driver=com.mysql.jdbc.Driver
#在和mysql传递数据的过程中，使用unicode编码格式，并且字符集设置为utf-8
url=jdbc:mysql://127.0.0.1:3306/smbms?useSSL=false&useUnicode=true&characterEncoding=utf-8
user=root
password=root

     
    
    
     
    
    
     
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     2
     
     3
     
     4
     
     5

2、编写数据库的公共类

package dao;