package com.scv.servlet;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class JdbcUtil {
public staticvoidmain(String[] args){
JdbcUtil jdbcUtil =new JdbcUtil();
List list=jdbcUtil.findAllUsers();for(int i =0; i < list.size(); i++){
System.out.println(list.get(i));}}
public voidaddUser(String username,String password){//1.加载驱动
try {
Class.forName("com.mysql.jdbc.Driver");//2.创建链接
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/qqs","root","123456");//3.
PreparedStatement ps=conn.prepareStatement("insert into user (username,password) value(?,?)");
ps.setString(1, username);
ps.setString(2, password);
ps.execute();
ps.close();
conn.close();} catch (ClassNotFoundException e){// TODO Auto-generated catch block
e.printStackTrace();} catch (SQLException e){// TODO Auto-generated catch block
e.printStackTrace();}}
public voidupdateUser(String username,String password){//1.加载驱动
try {
Class.forName("com.mysql.jdbc.Driver");//2.创建链接
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/qqs","root","123456");//3.
PreparedStatement ps=conn.prepareStatement(" update user set password=? where username=?");
ps.setString(1, password);//替换占位符
ps.setString(2, username);
ps.execute();
ps.close();
conn.close();} catch (ClassNotFoundException e){// TODO Auto-generated catch block
e.printStackTrace();} catch (SQLException e){// TODO Auto-generated catch block
e.printStackTrace();}}
public voiddeleteUserByName(String username){//1.加载驱动
try {
Class.forName("com.mysql.jdbc.Driver");//2.创建链接
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/qqs","root","123456");//3.
PreparedStatement ps=conn.prepareStatement("delete from user where username=?");
ps.setString(1,username);
ps.execute();
conn.close();
ps.close();} catch (ClassNotFoundException e){// TODO Auto-generated catch block
e.printStackTrace();} catch (SQLException e){// TODO Auto-generated catch block
e.printStackTrace();}}
public List findAllUsers(){
List<User> list = new ArrayList<User>();//1.加载驱动
try {
Class.forName("com.mysql.jdbc.Driver");//2.创建链接
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/qqs","root","123456");//3.
PreparedStatement ps=conn.prepareStatement("select * from user ");
ResultSet resultSet=ps.executeQuery();while(resultSet.next()){
String uname= resultSet.getString("username");
String pwd= resultSet.getString("password");int qq= resultSet.getInt("qq");
User user = new User();//实例化一个user对象
user.setUsername(uname);//为user对象赋值
user.setPassword(pwd);
user.setQq(qq);
list.add(user);//把user对象放入到全局变量list中}} catch (ClassNotFoundException e){// TODO Auto-generated catch block
e.printStackTrace();} catch (SQLException e){// TODO Auto-generated catch block
e.printStackTrace();}return list;}
public User findUserByName(String username){
User user =new User();
try {//数据库操作//1.加载驱动
Class.forName("com.mysql.jdbc.Driver");//2.创建链接
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/qqs","root","123456");//3.
PreparedStatement ps=conn.prepareStatement("select * from user where username=?");
ps.setString(1, username);//使用参数username替代？//4.获取查询结果
ResultSet res= ps.executeQuery();while(res.next()){
String uname= res.getString("username");
String pwd= res.getString("password");int qq= res.getInt("qq");
user.setUsername(username);
user.setPassword(pwd);
user.setQq(qq);}//关闭数据
ps.close();
conn.close();} catch (ClassNotFoundException e){// TODO Auto-generated catch block
e.printStackTrace();} catch (SQLException e){// TODO Auto-generated catch block
e.printStackTrace();}return user;}}
package com.scv.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.scv.servlet.JdbcUtil;
import com.scv.servlet.User;
public class Myservlet extends HttpServlet {/**
* Constructor of the object.
*/
public Myservlet(){super();}/**
* Destruction of the servlet. <br>
*/
public voiddestroy(){
super.destroy();// Just puts "destroy" string in log// Put your code here}/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public voiddoGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String uname= request.getParameter("username");
String pwd= request.getParameter("password");
JdbcUtil jdbcUtil =new JdbcUtil();
User user =jdbcUtil.findUserByName(uname);if(uname.equals(user.getUsername())&&pwd.equals(user.getPassword())){
request.getRequestDispatcher("success.jsp").forward(request, response);}else{
request.getRequestDispatcher("fail.jsp").forward(request, response);}}/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public voiddoPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {doGet(request, response);}/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public voidinit() throws ServletException {// Put your code here}}
package com.scv.servlet;
public class User {
private int qq;
private String username;
private String password;
public intgetQq(){return qq;}
public voidsetQq(int qq){
this.qq = qq;}
public String getUsername(){return username;}
public voidsetUsername(String username){
this.username = username;}
public String getPassword(){return password;}
public voidsetPassword(String password){
this.password = password;}
@Override
public String toString(){return"User [qq="+ qq +", username="+ username +", password="+ password +"]";}}
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><base href="<%=basePath%>"><title>My JSP 'success.jsp' starting page</title><meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0"><meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">--></head><body>
登录失败 </body></html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><base href="<%=basePath%>"><title>My JSP 'login.jsp' starting page</title><meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0"><meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">--></head><body><form action="servlet/myservlet"><input type="text" name="username"><input type="text" name="password"><input type="submit" value="登陆"></form></body></html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><base href="<%=basePath%>"><title>My JSP 'success.jsp' starting page</title><meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0"><meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">--></head><body>
登录成功 <br></body></html>
