前端发送post请求，如何跟后端交互http://www.cnblogs.com/huhuuu/p/3993019.html

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前端发送post请求，如何跟后端交互

Posted on 2014-09-25 16:07 huhuuu 阅读(2619) 评论(0) 编辑收藏

假如，现在我做了一个给用户使用的html页面：

<!DOCTYPE html><html><head><meta charset="UTF-8"><title>Insert title here</title></head><h1>helloPost!</h1><body><form method="post" action="SelectBeer.do">    <p>Select beer</p>    <select name="color" size="1">        <option value="light"> light</option>        <option value="amber"> amber</option>        <option value="brown"> brown</option>        <option value="dark"> dark</option>    </select>    <center>        <input type="submit">    </center></form>></body></html>

<form method="post" action="SelectBeer.do"> 中的SelectBeer.do有点像资源名。最终会被http:/127.0.0.1:8080/文件名/SelectBeer.do 的形式访问到。这是我又写了后台servlet程序，实现了get,post的方法：

package com.example.web;import java.io.IOException;import java.io.PrintWriter;import java.sql.Time;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class HelloWorld2 */@WebServlet("/HelloWorld2")public class HelloWorld2 extends HttpServlet {    private static final long serialVersionUID = 1L;    /**     * Default constructor.      */    public HelloWorld2() {        // TODO Auto-generated constructor stub                    }    /**     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)     */    @SuppressWarnings("deprecation")    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        // TODO Auto-generated method stub        PrintWriter out = response.getWriter();        //out.print("helloWorld");                //String outPut=request.getParameter("input");        out.print(request);        System.out.println(request);                String c = request.getParameter("color");    }    /**     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)     */    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        // TODO Auto-generated method stub        response.setContentType("text/html");        PrintWriter out = response.getWriter();        out.println("Beer Selection Advice<br>");        String c = request.getParameter("color");        out.println("<br> Got beer color"+c);                System.out.println(c);                    }}

把html放到servlet目录下，发现前后端无法通信。

这时还需要在web.xml下进行设置。

      <servlet>          <servlet-name>123123</servlet-name>          <servlet-class>com.example.web.HelloWorld2</servlet-class>      </servlet>        <servlet-mapping>        <servlet-name>123123</servlet-name>        <url-pattern>/SelectBeer.do</url-pattern>    </servlet-mapping>

servlet：可以自己设置servlet的资源名字， 然后写上对应的servlet类名

servlet-mapping：自己的servlet与资源的映射关系发送Post请求：

返回：

发送get请求：参考：head first,servlet & jsp

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