package com.demo;
import java.io.*;
import java.sql.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.WebServlet;
@WebServlet("/queryproduct.do")
public class QueryProductServlet extends HttpServlet{
private static final long serialVersionUID = 1L;
Connection dbconn = null;
public void init() {
String driver = "com.jdbc.mysql.Driver";
String dburl = "jdbc:mysql://localhost:3306/prod_data";
String username = "root";
String password = "123456";
try{
Class.forName(driver); // 加载驱动程序
// 创建连接对象
dbconn = DriverManager.getConnection(dburl,username,password);
}catch(ClassNotFoundException e1){
System.out.println(e1);
}catch(SQLException e2){}
}
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,IOException{
String productid = request.getParameter("productid");
try{
String sql="SELECT * FROM products WHERE prod_id = ?";
PreparedStatement pstmt = dbconn.prepareStatement(sql);
pstmt.setString(1,productid);
ResultSet rst = pstmt.executeQuery();
//System.out.println(sql);
if(rst.next()){
Product product = new Product();
product.setProd_id(rst.getString("prod_id"));
product.setPname(rst.getString("pname"));
product.setPrice(rst.getDouble("price"));
product.setStock(rst.getInt("stock"));
request.getSession().setAttribute("product", product);
response.sendRedirect("displayProduct.jsp");
}else{
response.sendRedirect("error.jsp");
}
}catch(SQLException e){
e.printStackTrace();
}
}
}
<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head><title>商品查询</title></head>
<body>
<form action = "queryproduct.do" method="post">
请输入商品号：
<input type = "text" name="productid" size="15">
<input type = "submit" value = "确定">
</form>
</body>
</html>
package com.demo;
import java.io.Serializable;
public class Product implements Serializable{
private String prod_id;
private String pname;
private double price;
private int stock;
public Product(){}
public Product(String prod_id, String pname, double price, int stock) {
this.prod_id = prod_id;
this.pname = pname;
this.price = price;
this.stock = stock;
}
public String getProd_id() {
return prod_id;
}
public void setProd_id(String prod_id) {
this.prod_id = prod_id;
}
public String getPname() {
return pname;
}
public void setPname(String pname) {
this.pname = pname;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public int getStock() {
return stock;
}
public void setStock(int stock) {
this.stock = stock;
}
}
错误如下：