Java ServerSocket getChannel() Method

The getChannel() method of the ServerSocket class is used to return the unique ServerSocketChannel object associated with this socket if any. A server socket will have a channel if, and only if, the channel itself was created via the ServerSocketChannel.open method.

Syntax

Returns:

The server-socket channel associated with this socket, or null if this socket was not created for a channel.

Since:

1.4

Example 1

import java.io.IOException;
import java.net.Socket;
import java.nio.channels.SocketChannel;

public class SocketGetChannel1 {
 public static void main(String[] args) throws Exception {
		    String serverName = args[0];
		    int port = Integer.parseInt(args[1]);
		    try {
			
		      System.out.println("Connecting to " + serverName + " on port "+port);
		      Socket client = new Socket(serverName, port);
		      System.out.println("Local Socket Address "+client.getLocalSocketAddress()); 
		   SocketChannel channel = client.getChannel();
 		    System.out.println("socket channel "+channel);  
			
			if(!client.isClosed())
			{
			System.out.println("Closing state of ServerSocket");     
			client.close();
			}
		        	
		    } catch (IOException e) {
		      e.printStackTrace();
		    }
		  }

Output:

Example 2

ServerApplication:

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketTimeoutException;
import java.nio.channels.ServerSocketChannel;

public class SocketGetChannel2 extends Thread {
  private ServerSocket serverSocket;

  public SocketGetChannel2 () throws IOException {
    serverSocket = new ServerSocket(1408);
    serverSocket.setSoTimeout(10000);    
    
    ServerSocketChannel channel = serverSocket.getChannel();
System.out.println("get Socket Channel " + channel);
  }

  public void run() {
    while (true) {
      try {
	Socket client = serverSocket.accept();
        System.out.println("Just connected to " + client.getRemoteSocketAddress());
        client.close();
      } catch (SocketTimeoutException s) {
        System.out.println("Socket timed out!");
        break;
      } catch (IOException e) {
        e.printStackTrace();
        break;
      }
    }
  }

  public static void main(String[] args) {
    try {
      Thread t = new SocketGetChannel2();
      t.start();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

Client Application

import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;

public class ClientApplication {

	public static void main(String arg[]) throws UnknownHostException,IOException
	{
	Socket s=new Socket("127.0.0.1",1408);
	System.out.println("Connected on Port " + s.getPort() + "...");
	}
}

Output: