Socket 客戶端實例

如下的 GreetingClient 是一個客戶端程序，該程序通過 socket 連接到服務器並發送一個請求，然後等待一個響應。

// 文件名 GreetingClient.java
 
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("連接到主機：" + serverName + " ，端口號：" + port);
         Socket client = new Socket(serverName, port);
         System.out.println("遠程主機地址：" + 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("服務器響應： " + in.readUTF());
         client.close();
      }
 
catch(IOException e)
      {
         e.printStackTrace();
      }
   }
}

Socket 服務端實例

如下的GreetingServer 程序是一個服務器端應用程序，使用 Socket 來監聽一個指定的端口。

// 文件名 GreetingServer.java
 
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("等待遠程連接，端口號為：" + serverSocket.getLocalPort() + "...");
            Socket server = serverSocket.accept();
            System.out.println("遠程主機地址：" + server.getRemoteSocketAddress());
            DataInputStream in = new DataInputStream(server.getInputStream());
            System.out.println(in.readUTF());
            DataOutputStream out = new DataOutputStream(server.getOutputStream());
            out.writeUTF("謝謝連接我：" + 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();
      }
   }
}

java-socket通信