创建数据库和表
sql语句:
DROP TABLE IF EXISTS product;CREATE TABLE product( product_id varchar(20) NOT NULL, product_name varchar(50) DEFAULT NULL, price decimal(6,2) DEFAULT NULL, info varchar(100) DEFAULT NULL, PRIMARY KEY(product_id))ENGINE=InnoDB DEFAULT CHARSET=utf8;
文件目录如下
Product.java
1 package com.g.pojo; 2 3 public class Product { 4 private String product_id; 5 private String product_name; 6 private double price; 7 private String info; 8 public String getProduct_id() { 9 return product_id;10 }11 public void setProduct_id(String product_id) {12 this.product_id = product_id;13 }14 public String getProduct_name() {15 return product_name;16 }17 public void setProduct_name(String product_name) {18 this.product_name = product_name;19 }20 public double getPrice() {21 return price;22 }23 public void setPrice(double price) {24 this.price = price;25 }26 public String getInfo() {27 return info;28 }29 public void setInfo(String info) {30 this.info = info;31 }32 33 34 35 }ProductDao.java代码
1 package com.g.dao; 2 3 import java.util.List; 4 5 import com.g.pojo.Product; 6 7 public interface ProductDao { 8 /** 9 * 数据库 新增数据10 * @param product 要增加的数据对象11 * @return是否增加成功的标志12 * @throws Exception 如果有异常,将直接抛出13 */14 public boolean addProduct(Product product) throws Exception;15 16 /**17 * 查询全部的Product18 * @param product_name 产品名称19 * @return返回全部的查询结果,每一个product对象表示表的一行记录20 * @throws Exception 如果有异常,将直接抛出21 */22 public List<Product> findAll(String product_name)throws Exception;23 24 /**25 * 根据产品编号查询产品26 * @param product_id 产品编号27 * @return 产品对象28 * @throws Exception 如果有异常,将直接抛出29 */30 public Product findByProductId(String product_id)throws Exception;31 32 }ProductService.java代码
1 package com.g.service; 2 3 import java.util.List; 4 5 import com.g.dao.ProductDao; 6 import com.g.dao.ProductDaoImpl; 7 import com.g.db.DBConnection; 8 import com.g.pojo.Product; 9 10 /**11 * 操作数据库12 * @author 思思博士13 *14 */15 public class ProductService implements ProductDao{16 17 private DBConnection dbconn=null;18 private ProductDao dao=null;19 //在构造方法中实例化数据库连接,同时实例化dao对象20 public ProductService() throws Exception{21 this.dbconn=new DBConnection();22 //实例化ProductDao的实现类23 this.dao=new ProductDaoImpl(this.dbconn.getConnection()); 24 } 25 public boolean addProduct(Product product) throws Exception {26 boolean flag=false;27 try{28 if(this.dao.findByProductId(product.getProduct_id())==null){29 //如果要插入的产品编号不存在30 flag=this.dao.addProduct(product);//新增一条产品信息31 }32 }33 catch (Exception e) {34 throw e;35 }finally{36 this.dbconn.close();37 }38 39 return flag;40 }41 42 public List<Product> findAll(String keyWord) throws Exception {43 List<Product> all=null; //定义产品返回的集合44 try {45 all=this.dao.findAll(keyWord);46 } catch (Exception e) {47 throw e;48 }finally{49 this.dbconn.close();50 }51 return all;52 }53 54 public Product findByProductId(String product_id) throws Exception {55 Product product=null;56 try {57 product=this.dao.findByProductId(product_id);58 } catch (Exception e) {59 throw e;60 }finally{61 this.dbconn.close();62 }63 return product;64 }65 }
DBConnection.java代码
1 package com.g.db; 2 3 import java.sql.Connection; 4 import java.sql.DriverManager; 5 6 public class DBConnection { 7 private static final String Driver="com.mysql.jdbc.Driver"; 8 private static final String Url="jdbc:mysql://127.0.0.1:3306/testweb"; 9 private static final String User="root";10 private static final String Password="gys";11 private Connection conn=null;12 13 //进行数据库连接14 public DBConnection() throws Exception{15 try{16 //用反射加载数据库驱动17 Class.forName(Driver);18 this.conn=DriverManager.getConnection(Url,User,Password);19 }20 catch (Exception e) {21 throw e;22 }23 }24 //取得数据库的连接25 public Connection getConnection(){26 return this.conn; 27 }28 //关闭数据库29 public void close() throws Exception{30 if(this.conn!=null){31 try {32 this.conn.close();33 34 } catch (Exception e) {35 throw e;36 }37 }38 }39 40 }
ProductDaoImpI.java代码
1 package com.g.dao; 2 3 import java.sql.Connection; 4 import java.sql.PreparedStatement; 5 import java.sql.ResultSet; 6 import java.util.ArrayList; 7 import java.util.List; 8 9 import com.g.pojo.Product;10 11 /**12 * 实现DAO接口的类.但是不负责数据库的打开和关闭13 * @author 思思博士14 *15 */16 public class ProductDaoImpl implements ProductDao{17 private Connection conn=null;18 private PreparedStatement pstmt=null;19 //通过构造方法取得数据库连接20 public ProductDaoImpl(Connection conn){21 this.conn=conn;22 }23 public boolean addProduct(Product product) throws Exception {24 boolean flag=false;25 String sql="insert into product(product_id,product_name,price,info) values(?,?,?,?)";26 this.pstmt=this.conn.prepareStatement(sql);27 this.pstmt.setString(1,product.getProduct_id());28 this.pstmt.setString(2,product.getProduct_name());29 this.pstmt.setDouble(3,product.getPrice());30 this.pstmt.setString(4,product.getInfo());31 32 if(this.pstmt.executeUpdate()>0){33 flag=true;34 }35 this.pstmt.close();36 return flag;37 }38 39 public List<Product> findAll(String product_name) throws Exception { 40 List<Product> list=new ArrayList<Product>();41 String sql="select product_id,product_name,price,info from product";42 if(product_name!=null&&!"".equals(product_name)){43 sql="select product_id,product_name,price,info from product where product_name like ?";44 this.pstmt=this.conn.prepareStatement(sql);45 this.pstmt.setString(1,"%"+product_name+"%");46 }47 else {48 this.pstmt=this.conn.prepareStatement(sql);49 }50 ResultSet rs=this.pstmt.executeQuery();51 Product product=null;52 while(rs.next()){53 product=new Product();54 product.setProduct_id(rs.getString(1));55 product.setProduct_name(rs.getString(2));56 product.setPrice(rs.getDouble(3));57 product.setInfo(rs.getString(4));58 list.add(product);59 }60 this.pstmt.close();61 return list;62 }63 64 public Product findByProductId(String product_id) throws Exception {65 Product product=null;66 String sql="select product_id,product_name,price,info from product where product_id=?";67 this.pstmt=this.conn.prepareStatement(sql);68 this.pstmt.setString(1,product_id);69 ResultSet rs=this.pstmt.executeQuery();70 if(rs.next()){71 product=new Product();72 product.setProduct_id(rs.getString(1));73 product.setProduct_name(rs.getString(2));74 product.setPrice(rs.getDouble(3));75 product.setInfo(rs.getString(4));76 }77 this.pstmt.close();78 return product;79 }80 81 82 }DAOFactory.java代码
1 package com.g.factory; 2 3 import com.g.dao.ProductDao; 4 import com.g.service.ProductService; 5 6 public class DAOFactory { 7 public static ProductDao getIEmpDAOInstance() throws Exception{ 8 //取得业务操作类 9 return new ProductService();10 }11 }TestInsertProduct.java代码
1 package com.g.test; 2 3 import com.g.factory.DAOFactory; 4 import com.g.pojo.Product; 5 6 public class TestInsertProduct { 7 public static void main(String[] args) { 8 Product product=null; 9 try {10 for(int i=0;i<5;i++){11 product=new Product();12 product.setProduct_id("350115001010"+i);13 product.setProduct_name("水杯"+i);14 product.setPrice(100+i);15 product.setInfo("这是一个精美的杯子"+i);16 DAOFactory.getIEmpDAOInstance().addProduct(product);17 }18 } catch (Exception e) {19 e.printStackTrace();20 }21 }22 }add.jsp代码
1 <%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%> 2 <% 3 String path = request.getContextPath(); 4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 5 %> 6 7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 8 <html> 9 <head>10 <base href="<%=basePath%>">11 12 <title>添加产品</title>13 </head>14 15 <body>16 <form action="insert.jsp" method="post">17 产品编号:<input name="product_id" /><br/>18 产品名称:<input name="product_name" /><br />19 产品价格:<input name="price" /><br/>20 产品信息:<textarea rows="5" cols="15" name="info"></textarea><br/>21 <input type="submit" value="添加" /> 22 <input type="reset" value="重置" />23 </form>24 </body>25 </html>
insert.jsp代码
1 <%@page import="com.g.factory.DAOFactory"%> 2 <%@page import="com.g.pojo.Product"%> 3 <%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%> 4 <% 5 String path = request.getContextPath(); 6 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 7 %> 8 9 <%10 request.setCharacterEncoding("utf-8");11 %>12 13 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">14 <html>15 <head>16 <base href="<%=basePath%>"> 17 <title>执行添加产品</title>18 </head>19 20 <body>21 <%22 Product product=new Product();23 product.setProduct_id(request.getParameter("product_id"));24 product.setProduct_name(request.getParameter("product_name"));25 product.setPrice(Double.parseDouble(request.getParameter("price")));26 product.setInfo(request.getParameter("info"));27 boolean flag=DAOFactory.getIEmpDAOInstance().addProduct(product);//执行添加操作28 if(flag){29 %>30 <h4>添加产品信息成功</h4>31 <%}else{%>32 <h4>添加产品信息失败.</h4>33 <%} %>34 </body>35 </html>list.jsp代码
1 <%@page import="com.g.factory.DAOFactory"%> 2 <%@page import="com.g.pojo.Product"%> 3 <%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%> 4 <% 5 String path = request.getContextPath(); 6 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 7 %> 8 <%request.setCharacterEncoding("utf-8"); %> 9 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">10 <html>11 <head>12 <base href="<%=basePath%>"> 13 <title>查询产品列表</title>14 </head>15 16 <body>17 <%18 String product_name=request.getParameter("product_name");19 if(product_name==null)20 product_name="";21 List<Product> list=DAOFactory.getIEmpDAOInstance().findAll(product_name);22 %>23 <form action="list.jsp" method="post">24 请输入产品名称:<input name="product_name" value="<%=product_name %>"/>25 <input type="submit" value="提交" />26 </form>27 <table>28 <tr>29 <td>产品编号</td>30 <td>产品名称</td>31 <td>产品价格</td>32 <td>产品信息</td>33 </tr>34 <%35 for(int i=0;i<list.size();i++){36 Product p=list.get(i);//取出每一个产品37 %>38 <tr>39 <td><%=p.getProduct_id() %></td>40 <td><%=p.getProduct_name() %></td>41 <td><%=p.getPrice() %></td>42 <td><%=p.getInfo() %></td>43 </tr>44 <%}%>45 46 47 </table>48 </body>49 </html>
原标题：java中的DAO设计模式
关键词：JAVA
我知道了 