java 模拟浏览器进行get和post请求

java 模拟浏览器进行get和post请求——本文参考《疯狂java讲义》

利用java的URLConnection能够模拟浏览器访问服务器的资源，下面是一个简答的例子：

package com.xueyoucto.xueyou;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.URL;import java.net.URLConnection;import java.util.List;import java.util.Map;/** * Hello world! */class GetPostTest {    public static String sendGet(String url, String param) {        String result = "";        String urlName = url + "?" + param;        try {            URL realURL = new URL(urlName);            URLConnection conn = realURL.openConnection();            conn.setRequestProperty("accept", "*/*");            conn.setRequestProperty("connection", "Keep-Alive");            conn.setRequestProperty("user-agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.106 Safari/537.36");            conn.connect();            Map<String, List<String>> map = conn.getHeaderFields();            for (String s : map.keySet()) {                System.out.println(s + "-->" + map.get(s));            }            BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "utf-8"));            String line;            while ((line = in.readLine()) != null) {                result += "\n" + line;            }        } catch (IOException e) {            e.printStackTrace();        }        return result;    }    public static String sendPost(String url,String param){        String result = "";        try {            URL realUrl = new URL(url);            URLConnection conn = realUrl.openConnection();            conn.setRequestProperty("accept", "*/*");            conn.setRequestProperty("connection", "Keep-Alive");            conn.setRequestProperty("user-agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.106 Safari/537.36");            //post设置如下两行            conn.setDoOutput(true);            conn.setDoInput(true);            PrintWriter out = new PrintWriter(conn.getOutputStream());            out.print(param);            out.flush();            BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream(),"utf-8"));            String line;            while((line = in.readLine()) != null){                result +="\n" + line;            }        } catch (IOException e) {            e.printStackTrace();        }        return result;    }}public class App {    public static void main(String[] args) throws Exception {        System.out.println("hello world");        String sendRecvGet =GetPostTest.sendGet("http://localhost:8989/testServletEncoding/encodingTest","param=xxxxx嘻嘻嘻");        System.out.println(sendRecvGet);        String sendRecvPost =GetPostTest.sendPost("http://localhost:8989/testServletEncoding/encodingTest","param=就是我");        System.out.println(sendRecvPost);    }}

下面是运行结果：

服务器端就是简单的servlet，根据客户端给出的参数进行返回：

package com.xueyoucto.xueyou;import javax.servlet.ServletException;import javax.servlet.ServletOutputStream;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.io.OutputStream;import java.io.PrintWriter;import java.io.UnsupportedEncodingException;/** * Created by Administrator on 2016-09-08. */@WebServlet(name = "EncodingTestServlet",urlPatterns = "/encodingTest")public class EncodingTestServlet extends HttpServlet {    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doGet(request,response);    }    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        request.setCharacterEncoding("utf-8");        response.setHeader("content-type","text/html;charset=UTF-8");        String s = request.getParameter("param");        System.out.println(s);        PrintWriter printWriter = response.getWriter();        printWriter.write(s);    }}