Java——简单代理服务器实现.doc

这个程序主要实现的是一个简单的代理功能。用户请求代理，代理请求指定页面再原封不动的传回客户端，代码如下：import java.io.*;import .*;import java.util.*;import java.awt.*;import javax.swing.*;public class ProxyServer extends JFrame private JTextArea jta =new JTextArea();/create an JTextArea to output some informationpublic static void main(String args)new ProxyServer();public ProxyServer() setLayout(new BorderLayout();add(new JScrollPane(jta), BorderLayout.CENTER);setTitle(Proxy Server by Li Zhaoji);setSize(500, 300);setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);setVisible(true);tryServerSocket serverSocket = new ServerSocket(8081);/Listening port 8081jta.append(Proxy Server started at + new Date() + n);jta.append(Proxy Server is listening on port +serverSocket.getLocalPort() + n + n);int clientNo = 1;while (true) Socket socket = serverSocket.accept();jta.append(1*1 + n);jta.append(Starting thread for client + clientNo + at + new Date() + n);InetAddress inetAddress = socket.getInetAddress();/get the host PCs informationjta.append(Client + clientNo + s host name is + inetAddress.getHostName() + n);jta.append(Client + clientNo + s IP Address is + inetAddress.getHostAddress() + n);HandleClient task = new HandleClient(socket);new Thread(task).start();/start a new thread to handle the require of the hostclientNo+;catch(IOException ex) System.err.println(ex);class HandleClient implements Runnable private Socket socket;public HandleClient(Socket socket)this.socket = socket;public void run() tryBufferedReader inputFromClient = new BufferedReader(new InputStreamReader(socket.getInputStream();PrintStream outputToClient = new PrintStream(socket.getOutputStream();String str = inputFromClient.readLine();/read the GET require string from Hostjta.append(The require from Client: + str + n);String inurl = str.substring(4, str.indexOf(HTTP/)-1);/get the URL string from GET jta.append(The require URL: + inurl + n);URL url = new URL(inurl);InputStream infile = url.openStream();/the input stream that get the data from Web Serverint n = infile.available();/the number of bytes that accept from Web Serverbyte buf = new byte1024;while(n = infile.read(buf) = 0)outputToClient.write(buf, 0, n);/start send with buf0, send n bytesoutputToClient.close();socket.close();inputFromClient.close();jta.append(socket has been closed! + n)