为什么在浏览器中显示不出数据库中Product这个表中的详细信息,只显示框架？？Product数据已经导入到数据库中
怎样解决？？？？就是在浏览器中不显示Product表的详细信息？？？一．Product.java
package entity;
public class Product {
private int productId;//商品ID、主键
private String name;//商品名称
private int catId;//商品所属类别，外键
private double price;//商品单价
private String desc;//商品描述信息
private String attr;//商品属性
public Product(){}
public Product(int productId,String name,int catId,double price,String desc,String attr)
{
this.productId = productId;
this.name = name;
this.catId = catId;
this.price = price;
this.desc = desc;
this.attr = attr;
}
public int getProductId() {
return productId;
}
public void setProductId(int productId) {
this.productId = productId;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getCatId() {
return catId;
}
public void setCatId(int catId) {
this.catId = catId;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public String getDesc() {
return desc;
}
public void setDesc(String desc) {
this.desc = desc;
}
public String getAttr() {
return attr;
}
public void setAttr(String attr) {
this.attr = attr;
}
}
二．操作类：ProductDao.java
package dao;
import java.util.*;
import java.sql.*;
public class ProductDao {
public List<entity.Product> searchAll(){
List<entity.Product> list = new ArrayList<entity.Product>();
try {
Connection con=ConnectionManager.getConnection();
Statement stmt = con.createStatement();
String sql = "select * from product";
ResultSet res = stmt.executeQuery(sql);
while(res.next()){
entity.Product product = new entity.Product();
product.setProductId(res.getInt("productId"));
product.setName(res.getString("name"));
product.setCatId(res.getInt("catId"));
product.setPrice(res.getDouble("price"));
product.setDesc(res.getString("desc"));
product.setAttr(res.getString("attr"));
list.add(product);
}
res.close();
stmt.close();
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return list;
}
/*
* 通过CatId查询某一类别的商品
*/
public List<entity.Product> searchByCat(int catId){
List<entity.Product> list = new ArrayList<entity.Product>();
try {
Connection con=ConnectionManager.getConnection();
String sql = "select * from product where CatId=?";
PreparedStatement pstmt = con.prepareStatement(sql);
pstmt.setInt(1, catId);
ResultSet res =pstmt.executeQuery();
while(res.next()){
entity.Product product = new entity.Product();
product.setProductId(res.getInt("productId"));
product.setName(res.getString("name"));
product.setCatId(res.getInt("catId"));
product.setPrice(res.getDouble("price"));
product.setDesc(res.getString("desc"));
product.setAttr(res.getString("attr"));
list.add(product);
}
res.close();
pstmt.close();
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return list;
}
public List<entity.Product> searchBy(int productId){
List<entity.Product> list = new ArrayList<entity.Product>();
try {
Connection con=ConnectionManager.getConnection();
String sql = "select * from product where ProductId=?";
PreparedStatement pstmt = con.prepareStatement(sql);
pstmt.setInt(1, productId);
ResultSet res =pstmt.executeQuery();
while(res.next()){
entity.Product product = new entity.Product();
product.setProductId(res.getInt("productId"));
product.setName(res.getString("name"));
product.setCatId(res.getInt("catId"));
product.setPrice(res.getDouble("price"));
product.setDesc(res.getString("desc"));
product.setAttr(res.getString("attr"));
list.add(product);
}
res.close();
pstmt.close();
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return list;
}
/*
* 向数据库对应的表中增加新的产品
*/
public int Add(entity.Product product){
int result=0;
try {
Connection con = ConnectionManager.getConnection();
String sql = "insert into product values(null,?,?,?,?,?)";
PreparedStatement pstmt = con.prepareStatement(sql);
pstmt.setString(1, product.getName());
pstmt.setInt(2, product.getCatId());
pstmt.setDouble(3, product.getPrice());
pstmt.setString(4, product.getDesc());
pstmt.setString(5, product.getAttr());
result=pstmt.executeUpdate();
pstmt.close();
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return result;
}
/*
* 根据produtId删除商品
*/
public int Del(int productId){
int result=0;
try {
Connection con = ConnectionManager.getConnection();
String sql="delete from product where productId=?";
PreparedStatement pstmt=con.prepareStatement(sql);
pstmt.setInt(1, productId);
result=pstmt.executeUpdate();
pstmt.close();
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return result;
}
/*
* 更新指定productId的商品的信息
*/
public int Update(entity.Product product){
int result=0;
try {
Connection con = ConnectionManager.getConnection();
String sql="update product set name=?,catId =?,price=?,attr=? where productId=?";
PreparedStatement pstmt=con.prepareStatement(sql);
pstmt.setString(1, product.getName());
pstmt.setInt(2, product.getCatId());
pstmt.setDouble(3, product.getPrice());
pstmt.setString(4, product.getAttr());
pstmt.setInt(5, product.getProductId());
result=pstmt.executeUpdate();
pstmt.close();
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return result;
}
public static void main(String[]args) {
// TODO Auto-generated method stub
List<entity.Product> products = null;
ProductDao test = new ProductDao();
products = test.searchByCat(1);
for(entity.Product product : products){
System.out.println(product.getName());
}
}
}
三．JSP显示：displayProduct.jsp
<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312"%>
<%@page import="java.util.List"%>
<%@page import="entity.Product"%>
<jsp:useBean id="ProductDao" class="dao.ProductDao" />
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>Insert title here</title>
</head>
<%if(session.getAttribute("USER")==null)
response.sendRedirect("login.jsp");
%>
<%
List<Product> list=ProductDao.searchAll();
%>
<body>
<form name="form1" method="post" action="">
<p align="center">商品信息一览表</p>
<table width="664" border="1" align="center">
<tr>
<th width="183" height="25" scope="col">名称</th>
<th width="77" scope="col">价格</th>
<th width="200" scope="col">描述信息</th>
<th width="76" scope="col">属性</th>
</tr>
<%for(int i=0;i<list.size();i++){
Product product=(Product)list.get(i);
%>
<tr>
<td height="26"><%=product.getName() %></td>
<td><%=product.getPrice() %></td>
<td><%=product.getDesc() %></td>
<td><%=product.getAttr() %></td>
</tr>
<%} %>
</table>
<center><a href="SearchByType.jsp">查询</a></center>
<p> </p>
</form>
</body>
</html>
