创建一个web项目,完成增删查的操作 mobile

mobile.dao包

BaseDao.java

package mobile.dao;

import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;


import mobile.util.JdbcUtil;

public abstract class BaseDao<T> {
	
	public List<T> getList(Class<T> clazz, String sql, Object... params) {
		List<T> list = new ArrayList<>();
		Connection conn = JdbcUtil.getConnection();
		PreparedStatement stmt = null;
		ResultSet rs = null;

		try {
			stmt = conn.prepareStatement(sql);
			// 缁欏崰浣嶇锛熻祴鍊�
			for (int i = 0; i < params.length; i++) {
				stmt.setObject(i + 1, params[i]);
			}
			rs = stmt.executeQuery();
			// 浠庣粨鏋滈泦涓幏鍙栨墍鏈夌殑瀛楁
			ResultSetMetaData md = rs.getMetaData();
			while (rs.next()) {

				// 鐢ㄥ弽灏勫垱寤轰竴涓璞�
				T obj = clazz.newInstance();
				// 閬嶅巻鎵�湁鐨勫瓧娈�
				for (int i = 1; i <= md.getColumnCount(); i++) {
					// 鑾峰彇褰撳墠鍒楃殑鍒楀悕锛屽鏋滃垪鏈夊埆鍚嶏紝灏辫繑鍥炲埆鍚�
					String columnName = md.getColumnLabel(i).toLowerCase();
					// 鑾峰彇瀛楁鐨勫�
					Object columnValue = rs.getObject(columnName);			
					if (columnValue == null) {
						// 缁撴潫鏈寰幆
						continue;
					}
					// 鑾峰彇瀛楁鍊肩殑绠�煭绫诲瀷,渚嬪String,Integer
					String type = columnValue.getClass().getSimpleName();
					// oracle浼氬皢number绫诲瀷鐨勫瓧娈佃В鏋愭垚BigDecimal绫诲瀷,mysql浼氬皢int鍜宨nteger绫诲瀷瑙ｆ瀽鎴恑nt鎴朓nteger绫诲瀷
					switch (type) {
					case "BigDecimal":
						// 濡傛灉鍊奸噷闈㈡湁"."锛岃褰撴垚灏忔暟鏉ヨ幏鍙�
						if (columnValue.toString().contains(".")) {
							columnValue = rs.getDouble(columnName);
						} else {
							columnValue = rs.getInt(columnName);
						}
						break;
					case "int":
					case "Integer":
						columnValue = rs.getInt(columnName);
						break;
					}

					// System.out.println("鍒楀悕锛� + columnName + "锛屽瓧娈靛�锛� +
					// columnValue + "锛岀被鍨嬶細" + type);
					// 灏嗚幏鍙栧埌鐨勫瓧娈电殑鍊煎皝瑁呭埌璇ュ瓧娈靛搴旂殑鍚屽悕灞炴�涓�
					// 鑾峰彇绉佹湁灞炴�锛屾牴鎹睘鎬у悕鑾峰彇
					Field field = clazz.getDeclaredField(columnName);
					// 鍘婚櫎绉佹湁灞炴�璁块棶闄愬埗
					field.setAccessible(true);
					// 灏嗗瓧娈靛�璧嬬粰瀵硅薄鐨勫悓鍚嶅睘鎬�
					field.set(obj, columnValue);
				}
				// System.out.println("*****************************************");
				// 灏嗗璞℃坊鍔犲埌闆嗗悎涓�
				list.add(obj);

			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			mobile.util.JdbcUtil.closeAll(rs, stmt, conn);
		}

		return list;
	}

	public T getBean(Class<T> clazz, String sql, Object... params) {
		// 鍒涘缓瑕佽繑鍥炵殑瀵硅薄
		T obj = null;
		Connection conn = mobile.util.JdbcUtil.getConnection();
		PreparedStatement stmt = null;
		ResultSet rs = null;

		try {
			stmt = conn.prepareStatement(sql);
			// 缁欏崰浣嶇锛熻祴鍊�
			for (int i =0 ; i < params.length; i++) {
				stmt.setObject(i + 1, params[i]);
			}
			rs = stmt.executeQuery();
			// 浠庣粨鏋滈泦涓幏鍙栨墍鏈夌殑瀛楁
			ResultSetMetaData md = rs.getMetaData();
			if (rs.next()) {
				// 鐢ㄥ弽灏勫垱寤哄璞�
				obj = clazz.newInstance();
				// 閬嶅巻鎵�湁鐨勫瓧娈�
				for (int i = 1; i <= md.getColumnCount(); i++) {
					// 鑾峰彇褰撳墠鍒楃殑鍒楀悕锛屽鏋滃垪鏈夊埆鍚嶏紝灏辫繑鍥炲埆鍚�
					String columnName = md.getColumnLabel(i).toLowerCase();
					// 鑾峰彇瀛楁鐨勫�
					Object columnValue = rs.getObject(columnName);
					if (columnValue == null) {
						// 缁撴潫鏈寰幆
						continue;
					}
					// 鑾峰彇瀛楁鍊肩殑绠�煭绫诲瀷,渚嬪String,Integer
					String type = columnValue.getClass().getSimpleName();
					// oracle浼氬皢number绫诲瀷鐨勫瓧娈佃В鏋愭垚BigDecimal绫诲瀷,mysql浼氬皢int鍜宨nteger绫诲瀷瑙ｆ瀽鎴恑nt鎴朓nteger绫诲瀷
					switch (type) {
					case "BigDecimal":
						// 濡傛灉鍊奸噷闈㈡湁"."锛岃褰撴垚灏忔暟鏉ヨ幏鍙�
						if (columnValue.toString().contains(".")) {
							columnValue = rs.getDouble(columnName);
						} else {
							columnValue = rs.getInt(columnName);
						}
						break;
					case "int":
					case "Integer":
						columnValue = rs.getInt(columnName);
						break;
					}

					// System.out.println("鍒楀悕锛� + columnName + "锛屽瓧娈靛�锛� +
					// columnValue + "锛岀被鍨嬶細" + type);
					// 灏嗚幏鍙栧埌鐨勫瓧娈电殑鍊煎皝瑁呭埌璇ュ瓧娈靛搴旂殑鍚屽悕灞炴�涓�
					// 鑾峰彇绉佹湁灞炴�锛屾牴鎹睘鎬у悕鑾峰彇
					Field field = clazz.getDeclaredField(columnName);
					// 鍘婚櫎绉佹湁灞炴�璁块棶闄愬埗
					field.setAccessible(true);
					// 灏嗗瓧娈靛�璧嬬粰瀵硅薄鐨勫悓鍚嶅睘鎬�
					field.set(obj, columnValue);
				}

			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			mobile.util.JdbcUtil.closeAll(rs, stmt, conn);
		}

		return obj;
	}
}

MobileDao.java

package mobile.dao;

import java.util.List;



import mobile.entity.Mobile;

public interface MobileDao {
    int insert(Mobile  stu);
    int update(Mobile  stu);
    int delete(Integer  id);
    List<Mobile>queryAll();
    
    Mobile  queryById(Integer id);
}

mobileDaoImpl包

MobileDaoImpl.java

package mobile.daoImpl;

import java.util.List;

import mobile.dao.BaseDao;
import mobile.dao.MobileDao;
import mobile.entity.Mobile;
import mobile.util.JdbcUtil;

public class MobileDaoImpl extends BaseDao<Mobile> implements MobileDao{

	//鎻掑叆鏂规硶閲嶅啓
	public int insert(Mobile mob) {
		String sql="insert into mobile(brand,model,price,totalnum) values(?,?,?,?)";
		int i=JdbcUtil.executeUpdate(sql, mob.getBrand(),mob.getModel(),mob.getPrice(),mob.getTotalnum());
		return i;
	}
	//淇敼鎵嬫満淇℃伅
	public int update(Mobile mob) {
		String sql="update mobile set brand=?,model=?,price=?,totalnum=? where id=?";
		int i=JdbcUtil.executeUpdate(sql, mob.getBrand(),mob.getModel(),mob.getPrice(),mob.getTotalnum(),mob.getId());
		return i;
	}
	//鍒犻櫎鎵嬫満淇℃伅
	public int delete(Integer id) {
		String sql="delete from mobile where id=?";
		int i=JdbcUtil.executeUpdate(sql, id);
		return i;
	}
	//鏌ヨ鍏ㄩ儴鎵嬫満淇℃伅
	public List<Mobile> queryAll() {
		String sql="select * from mobile";
		List<Mobile>list=this.getList(Mobile.class, sql);
		return list;
	}
	//鏍规嵁ID鏌ヨ鎵嬫満淇℃伅
	public Mobile queryById(Integer id) {
	String sql="select * from mobile where id=?";
	Mobile mob=this.getBean(Mobile.class, sql, id);
		return mob;
	}
}

mobile.entity包

Mobile.java

package mobile.entity;

public class Mobile {
		private Integer id;
		private String brand;
		private String model;
		private Double price;
		private Integer totalnum;
		public Integer getId() {
			return id;
		}
		public void setId(Integer id) {
			this.id = id;
		}
		public String getBrand() {
			return brand;
		}
		public void setBrand(String brand) {
			this.brand = brand;
		}
		public String getModel() {
			return model;
		}
		public void setModel(String model) {
			this.model = model;
		}
		public Double getPrice() {
			return price;
		}
		public void setPrice(Double price) {
			this.price = price;
		}
		public Integer getTotalnum() {
			return totalnum;
		}
		public void setTotalnum(Integer totalnum) {
			this.totalnum = totalnum;
		}
		public Mobile(Integer id, String brand, String model, Double price, Integer totalnum) {
			super();
			this.id = id;
			this.brand = brand;
			this.model = model;
			this.price = price;
			this.totalnum = totalnum;
		}
		public Mobile() {
			super();
			// TODO Auto-generated constructor stub
		}
		@Override
		public String toString() {
			return "Mobile [id=" + id + ", name=" + brand + ", model=" + model + ", price=" + price + ", totalnum="
					+ totalnum + "]";
		}
		
		
}

mobile.util

package mobile.util;

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

/**
 * jdbc鎿嶄綔鏁版嵁搴撶殑宸ュ叿绫�灏佽閫氱敤鐨勪唬鐮�
 * 
 * @author lujun
 *
 */
public class JdbcUtil {
	// 鏁版嵁搴撻┍鍔ㄧ被
	private static String driver;
	// 鏁版嵁搴撴湇鍔″櫒鐨勫湴鍧�
	private static String url;
	// 杩炴帴鏈嶅姟鍣ㄧ殑鐢ㄦ埛鍚�
	private static String user;
	// 杩炴帴鏈嶅姟鍣ㄧ殑鐢ㄦ埛瀵嗙爜
	private static String password;
	// 鍔犺浇椹卞姩鍙渶瑕佸姞杞戒竴娆★紝鍙互鏀惧埌闈欐�浠ｇ爜鍧椾腑
	static {
		try {

			// 瀵筪b.properties鏂囦欢鐨勮鍙�
			Properties prop = new Properties();
			// 鍔犺浇鏂囦欢锛屽苟杞崲涓鸿緭鍏ユ祦锛屼粠娴佷腑璇诲彇鏁版嵁
			InputStream stream = JdbcUtil.class.getResourceAsStream("/db.properties");
			prop.load(stream);
			// 璋冪敤getProperty(String key)锛屾牴鎹甼ey鑾峰彇鐩稿簲鐨剉alue
			url = prop.getProperty("url");
			user = prop.getProperty("user");
			password = prop.getProperty("password");
			driver = prop.getProperty("driver");
			// 鍔犺浇椹卞姩
			Class.forName(driver);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	// 鑾峰彇涓�釜杩炴帴
	public static Connection getConnection() {
		Connection conn = null;
		try {
			conn = DriverManager.getConnection(url, user, password);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return conn;
	}

	// 鍏抽棴璧勬簮
	public static void closeAll(ResultSet rs, Statement stmt, Connection conn) {
		if (rs != null) {
			try {
				rs.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if (stmt != null) {
			try {
				stmt.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if (conn != null) {
			try {
				conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}

	/*
	 * 閫氱敤澧炲垹鏀规柟娉�鍙傛暟1锛氳鎵ц鐨凞ML璇彞(insert,update,delete璇彞)
	 * 鍙傛暟2锛氱粰DML璇彞涓殑锛熻祴鐨勪竴缁勫�,鎶婂崰浣嶇鍊肩粺涓�斁鍒板彲鍙樺弬鏁颁腑锛屽彲鍙樺弬鏁板彲浠ュ綋鎴愭暟缁勭敤
	 * 杩斿洖鍊硷細鎵ц澧炲垹鏀瑰奖鍝嶆暟鎹簱鐨勮鏁帮紝濡傛灉鎴愬姛锛岃繑鍥�锛屽け璐ヨ繑鍥�
	 */

	public static int executeUpdate(String sql, Object... params) {
		int count = 0;
		// 鍒涘缓杩炴帴
		Connection conn = JdbcUtil.getConnection();
		PreparedStatement stmt = null;
		try {
			// 鍒涘缓棰勭紪璇戠殑statement
			stmt = conn.prepareStatement(sql);
			// 缁欏崰浣嶇?璧嬪�
			for (int i = 0; i < params.length; i++) {
				stmt.setObject(i + 1, params[i]);
			}
			count = stmt.executeUpdate();

		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();

		} finally {
			// 鍏抽棴璧勬簮
			JdbcUtil.closeAll(null, stmt, conn);
		}
		return count;
	}
}

db.properties

 
#key=value
driver=com.mysql.jdbc.Driver
url = jdbc:mysql://127.0.0.1:3306/mysqldb
user=root
password=tiger

WebRoot

index.jsp

<%@ 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 'index.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>
      <a href="list.jsp">显示所有手机信息</a>
  </body>
</html>

list.jsp

<%@page import="mobile.daoImpl.MobileDaoImpl"%>
<%@page import="mobile.entity.Mobile"%>
<%@page import="mobile.dao.MobileDao"%>
<%@ 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 'list.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>
  		<h2>手机列表</h2>
  		<table width="50%" border="1" cellspacing="0" cellpadding="10">
		<tr>
			<td>手机编号</td>
			<td>品牌</td>
			<td>型号</td>
			<td>价格</td>
			<td>总数</td>
		</tr>
		<%
			MobileDao dao=new MobileDaoImpl();
			List<Mobile>list=dao.queryAll();
			for(Mobile mob:list){
		%>
		<tr>
			<td><%=mob.getId()%></td>
			<td><%=mob.getBrand()%></td>
			<td><%=mob.getModel()%></td>
			<td><%=mob.getPrice()%></td>
			<td><%=mob.getTotalnum() %></td>
		<td>
            <!-- 如果点超链接时，需要响应js事件，那么建议把href写成
            javascript:void(0)或者javascript:;表示让超链接不作任何跳转，只响应js事件 -->
          <a href="javascript:void(0)" onclick="deleteById(<%=mob.getId()%>)" >删除</a></td>

		</tr>
		<%
			}
		%>
		
	</table>
    <a href="add.jsp">添加手机</a>
    <script>
    	function deleteById(id){
    			 // confirm()函数会弹出一带确认和取消按钮的对话框，如果点击确认按钮，函数返回true,否则返回false
         var flag=  confirm('是否确认删除此记录'); 
    	 if(flag){
    		//alert(id);
    		//发送请求给doDelete.jsp页面, location.href是改变请求的路径，发送get请求
    	    location.href="doDelete.jsp?id="+id;
    	 }
    	}
    </script>
     <br>
  </body>
</html>

add.jsp

<%@ 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 'add.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>
  <h2>添加手机页面</h2>
    <form action="doAdd.jsp" method="post">
    品牌:<input type="text" name="brand"> <br>
    型号:<input type="text" name="model"> <br>
    价格:<input type="text" name="price"> <br>
    总数:<input type="text" name="totalnum"> <br>
  <input type="submit" value="添加新的手机">
     <br>
     </from>
  </body>
</html>

doAdd.jsp

<%@page import="mobile.entity.Mobile"%>
<%@page import="mobile.daoImpl.MobileDaoImpl"%>
<%@page import="mobile.dao.MobileDao"%>
<%@ 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 'doAdd.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>
    	<%
    	//设置请求编码,防止中文乱码
    	request.setCharacterEncoding("UTF-8");
    	String brand=request.getParameter("brand");
    	String model=request.getParameter("model");
    	double price=Double.parseDouble(request.getParameter("price"));
    	int  totalnum=Integer.parseInt(request.getParameter("totalnum"));
    	Mobile mob=new Mobile();
    	mob.setBrand(brand);;
    	mob.setModel(model);
    	mob.setPrice(price);
    	mob.setTotalnum(totalnum);
    	
    	MobileDao dao=new MobileDaoImpl();
    	int i=dao.insert(mob);
    	if(i>0){
    		//跳转到list.jsp页面,刷新页面,response.sendRedirect:重新发请求到新页面
    		response.sendRedirect("list.jsp");
    	}
    	
    	  %>
    <br>
  </body>
</html>

doDelete.jsp

<%@page import="mobile.dao.MobileDao"%>
<%@page import="mobile.daoImpl.MobileDaoImpl"%>
<%@ 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 'doDelete.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>
  		<% 
  		//获取要删除手机的编号
  		int id=Integer.parseInt(request.getParameter("id"));
  		//调用Dao的删除方法
  		MobileDao dao=new MobileDaoImpl();
  		int i=dao.delete(id);
  		if(i>0){
  				//跳转到list.jsp页面,刷新页面response.sendRedirect:重新发送请求到新的页面
  			response.sendRedirect("list.jsp");
  		}
  		%>
     <br>
  </body>
</html>