Java网络编程实例---------------------------------Java HTTP代理程序

在Internet设置代理服务器为127.0.0.1:8000 其他浏览器使用IE设置

package org.bq;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.StringTokenizer;

/**
 * 用Webkit内核浏览器可以运行成功，但是IE却有时候会出现问题
 * 返回到浏览器端的HTML不能正确显示，但的确是返回了
 * @author 白强
 * @version 1.0 2013-11-19
 * 
 */
public class Proxy {

    public Proxy() throws IOException {

        ServerSocket server = new ServerSocket(8000);
        int socketNo = 1;
        while (true) {
            Socket socket = server.accept();
            System.out.println("----Start For socket No" + socketNo + "------");
            System.out.println("The socket name ======="
                    + socket.getInetAddress().getHostName());
            ProxtThread task = new ProxtThread(socket);
            new Thread(task).start();
            socketNo++;
        }
    }

    public static void main(String[] args) throws Exception {
        new Proxy();
    }

}
class ProxtThread implements Runnable{
    
    private Socket socket;

    public ProxtThread(Socket socket) {
        this.socket=socket;
    }

    @Override
    public void run() {
        String reqs = "";
        String hostName = "";
        Integer port = 80;
        try{
        // 定义从浏览器得到的请求信息Reader
        
                BufferedReader serverReader = new BufferedReader(new InputStreamReader(
                        socket.getInputStream()));
                // 向浏览器返回数据
                PrintWriter serverWriter = new PrintWriter(socket.getOutputStream());
                String request = "";
                // 得到请求的首行
                request = serverReader.readLine();

                System.out.println(request);
                // 对首行进行分析,以空格为界拆分字符串
                StringTokenizer st = new StringTokenizer(request, " ");
                reqs = st.nextToken();
                System.out.println(reqs);
                // 得到请求URL
                String http = st.nextToken();
                String hostWithPort;
                if (http.startsWith("http://")) {
                    // 子串
                    hostWithPort = http.substring(7, http.indexOf("/", 7));
                    // 如果有冒号就是指定端口拆分
                    if (hostWithPort.indexOf(":") != -1) {
                        StringTokenizer stPort = new StringTokenizer(hostWithPort, ":");
                        hostName = stPort.nextToken();
                        port = new Integer(stPort.nextToken());
                    }
                    // 不然就是80了
                    else {
                        hostName = hostWithPort;
                        port = 80;
                    }
                    // 打印请求URL
                    System.out.println(hostName);
                }
                /*
                 * Ready，可以向Internet发送数据了
                 */
                Socket client = new Socket(hostName, port);

                PrintWriter clientWriter = new PrintWriter(client.getOutputStream());
                //我试过www.nwpu.edu.cn;www.baidu.com;www.163.com
                BufferedReader clientReader = new BufferedReader(new InputStreamReader(
                        client.getInputStream()));

                System.out.println("write to socket:" + request);

                int count = 0;
                while ((request != null) && (count < 8)) {
                    System.out.println(request);
                    count++;
                    if (request.contains("Accept-Encoding:")) {
                        System.out.println("contain:" + request);
                    } else
                        clientWriter.println(request);
                    request = serverReader.readLine();
                }
                clientWriter.println("
");
                clientWriter.flush();
                // 接受得到Response
                String response = new String();
                response = clientReader.readLine();

                System.out.println(response);

                while (!(response.equals(""))) {
                    System.out.println(response);
                    response = clientReader.readLine();

                }
                System.out.println(response);
                
                System.out.println("Start Receiving HTML ...");
                while ((response = clientReader.readLine()) != null) {
                    serverWriter.println(response);
                }

                serverWriter.flush();

                System.out.println("Finished!!!");
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
    
}