使用myeclipse“返回商品”步骤及代码(2015.09.15)

本文链接：https://blog.youkuaiyun.com/HPK8_CPH/article/details/48454551

1、创建工程file → new → Web Project ：ch2webprj1

2、file → new → HTML：search.html （编写search.html）

①编写form表单

<body>

</form>

</body>

② 指定action="goods.do"

3、编写与goods.do对应的服务器端程序

①src 下新建servlet ：GetGoodsServlet

只留下doGet和doPost

★ Servlet/JSP Mapping URL和action对应（如下图）

②在doGet方法里调用doPost

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

this.doPost(request, response);

}

③在doPost方法中设置编码格式、获取请求参数并输出（★请求参数需要和表单元素name值相同）

//设置编码格式

request.setCharacterEncoding("UTF-8");

response.setContentType("text/html;charset=utf-8");

//获取请求参数

String goods= request.getParameter("goods");

PrintWriter out = response.getWriter();

out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");

out.println("<HTML>");

out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");

out.println(" <BODY>");

//输出商品

out.println("您搜索的商品是：<br> ");

out.println(goods);

4、发布项目，将项目发布到tomcat

5、启动服务

6、测试

★备注：运行流程

Search.html → submit() → action=”good.do” → <url-pattern>★/goods.do</url-pattern> → <servlet-name> → <servlet-class> →设置编码格式UTF-8 →获取请求参数→输出网页信息

在前面的基础上输出商品

1、src下创建包：com.ch2.data

2、在com.ch2.data包下创建Goods类；（代码见附录三）

3、在com.ch2.data包下创建GoodsData类，模拟数据库（代码见附录四）

4、在GetGoodsServlet下编写运行程序（代码见附录五）

代码：

附录一：Search.html部分

<!DOCTYPE html>

<html>

<head>

<title>search.html</title>

</head>

<body>

</form>

</body>

</html>

附录二：Web.xml部分

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5"

xmlns="http://java.sun.com/xml/ns/javaee"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

<display-name></display-name>

<servlet-name>GetGoodsServlet</servlet-name>

<servlet-class>com.ch2.servlet.GetGoodsServlet</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>GetGoodsServlet</servlet-name>

<url-pattern>/goods.do</url-pattern>

</servlet-mapping>

<welcome-file-list>

<welcome-file>index.jsp</welcome-file>

</welcome-file-list>

</web-app>

附录三：Goods.java部分

package com.ch2.data;

public class Goods {

private int id;

private String name;

private String brand;

private double price;

private String color;

//无参

public Goods() {

super();

}

//有参

public Goods(int id, String name, String brand, int price, String color) {

super();

this.id = id;

this.name = name;

this.brand = brand;

this.price = price;

this.color = color;

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getBrand() {

return brand;

}

public void setBrand(String brand) {

this.brand = brand;

}

public double getPrice() {

return price;

}

public void setPrice(double price) {

this.price = price;

}

public String getColor() {

return color;

}

public void setColor(String color) {

this.color = color;

}

附录四：GoodsData.java部分

package com.ch2.data;

import java.util.*;

public class GoodsData {

//创建Goods集合

public static ArrayList<Goods> goodslist=new ArrayList<Goods>();

static{

//创建对象

Goods goods1=new Goods(1,"6p","苹果",5000,"黑色");

Goods goods2=new Goods(2,"P720","联想",1100,"红色");

Goods goods3=new Goods(3,"小米2","小米",500,"白色");

Goods goods4=new Goods(4,"华为","小米",500,"白色");

Goods goods5=new Goods(5,"荣耀","小米",500,"白色");

//添加到集合

goodslist.add(goods1);

goodslist.add(goods2);

goodslist.add(goods3);

goodslist.add(goods4);

goodslist.add(goods5);

}

附录五：GetGoodsServlet.java部分

package com.ch2.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.ch2.data.Goods;

import com.ch2.data.GoodsData;

import java.util.*;

public class GetGoodsServlet extends HttpServlet {

/**

* 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 void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

this.doPost(request, response);

/*response.setContentType("text/html");

PrintWriter out = response.getWriter();

out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");

out.println("<HTML>");

out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");

out.println(" <BODY>");

out.print(" This is ");

out.print(this.getClass());

out.println(", using the GET method");

out.println(" </BODY>");

out.println("</HTML>");

out.flush();

out.close();*/

}

/**

* 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 void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

//设置编码格式

request.setCharacterEncoding("UTF-8");

response.setContentType("text/html;charset=utf-8");

//获取请求参数

String goods= request.getParameter("goods");

PrintWriter out = response.getWriter();

out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");

out.println("<HTML>");

out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");

out.println(" <BODY>");

//输出商品

out.println("您搜索的商品是：<br> ");

out.println(goods);

//根据Goods的值查询数据，将数据库GoodsData与Goods相关的产品查询出来

//创建临时数据集合,存放查到的商品

ArrayList<Goods> templist=new ArrayList<Goods>();

//遍历GoodsData.goodslist

for(int i=0;i< GoodsData.goodslist.size();i++){

//从集合中逐个取出对象

Goods tempgoods=GoodsData.goodslist.get(i);

String name = tempgoods.getName();

if(name.indexOf(goods)!=-1){

templist.add(tempgoods);//将符合条件的对象添加到集合

}

//显示templist中的数据

if(templist.size()==0){

out.println("没有符合条件的商品<br>");

}else{

out.print("<table border=1 width='500' >");//以表格的形式输出

out.print("<tr>");

out.print("<td>编号</td>"); //表头固定元素

out.print("<td>名称</td>");

out.print("<td>品牌</td>");

out.print("<td>价格</td>");

out.print("<td>颜色</td>");

out.print("</tr>");

for(int i=0;i<templist.size();i++){

//取出对象

Goods findgoods = templist.get(i);

//out.println("编号"+findgoods.getId()+"名称："+findgoods.getName()+"品牌："+findgoods.getBrand()+"价格："+findgoods.getPrice()+"颜色"+findgoods.getColor()+"<br>");