JAVA网络编程（Socket 客户端与服务端）

Socket 客户端实例

如下的 GreetingClient 是一个客户端程序，该程序通过 socket 连接到服务器并发送一个请求，然后等待一个响应。

import java.net.*;
import java.io.*;
 
public class GreetingClient
{
   public static void main(String [] args)
   {
      String serverName = args[0];
      int port = Integer.parseInt(args[1]);
      try
      {
         System.out.println("连接到主机：" + serverName + " ，端口号：" + port);
         Socket client = new Socket(serverName, port);
         System.out.println("远程主机地址：" + client.getRemoteSocketAddress());
         OutputStream outToServer = client.getOutputStream();
         DataOutputStream out = new DataOutputStream(outToServer);
 
         out.writeUTF("Hello from " + client.getLocalSocketAddress());
         InputStream inFromServer = client.getInputStream();
         DataInputStream in = new DataInputStream(inFromServer);
         System.out.println("服务器响应： " + in.readUTF());
         client.close();
      }catch(IOException e)
      {
         e.printStackTrace();
      }
   }
}

Socket 服务端实例

如下的GreetingServer 程序是一个服务器端应用程序，使用 Socket 来监听一个指定的端口。

import java.net.*;
import java.io.*;
 
public class GreetingServer extends Thread
{
   private ServerSocket serverSocket;
   
   public GreetingServer(int port) throws IOException
   {
      serverSocket = new ServerSocket(port);
      serverSocket.setSoTimeout(10000);
   }
 
   public void run()
   {
      while(true)
      {
         try
         {
            System.out.println("等待远程连接，端口号为：" + serverSocket.getLocalPort() + "...");
            Socket server = serverSocket.accept();
            System.out.println("远程主机地址：" + server.getRemoteSocketAddress());
            DataInputStream in = new DataInputStream(server.getInputStream());
            System.out.println(in.readUTF());
            DataOutputStream out = new DataOutputStream(server.getOutputStream());
            out.writeUTF("谢谢连接我：" + server.getLocalSocketAddress() + "\nGoodbye!");
            server.close();
         }catch(SocketTimeoutException s)
         {
            System.out.println("Socket timed out!");
            break;
         }catch(IOException e)
         {
            e.printStackTrace();
            break;
         }
      }
   }
   public static void main(String [] args)
   {
      int port = Integer.parseInt(args[0]);
      try
      {
         Thread t = new GreetingServer(port);
         t.run();
      }catch(IOException e)
      {
         e.printStackTrace();
      }
   }
}