Java - Socket setSocketImplFactory() Method

Description

The Java Socket setSocketImplFactory(SocketImplFactory fac) is used to set the client socket implementation factory for the application. The factory can be specified only once. When an application creates a new client socket, the socket implementation factory's createSocketImpl method is called to create the actual socket implementation. Using null is a no-op unless the factory was already set. If there is a security manager, this method first calls the security manager's checkSetFactory method to ensure the operation is allowed. This could result in a SecurityException.

Declaration

Following is the declaration for java.net.Socket.setSocketImplFactory(SocketImplFactory fac) method.

public static void setSocketImplFactory(SocketImplFactory fac) throws IOException

Parameters

fac − the desired factory.

Return Value

NA

Exception

IOException − if an I/O error occurs when setting the socket factory.

SocketException − if the factory is already defined.

SecurityException − if a security manager exists and its checkSetFactory method doesn't allow the operation.

Example 1

The following example shows the usage of Java Socket setSocketImplFactory() method to set the client socket implementation factory for the application. As first step, we've created a Socket instance using no argument constructor. Then in order to create a SocketAddress object, we've initialized an InetAddress instance of localhost address. Here using setSocketImplFactory(), we set as no-op factory implementation. Using InetSocketAddress object, we've created a SocketAddress object and then using bind() method, we bind the address to the socket. Once done, we're setting the SO_SNDBUF value using setSendBufferSize() and then we're printing the SO_SNDBUF value using getSendBufferSize() method, local port and inetaddress as shown. In the end, we closed the socket using close() method.

package com.tutorialspoint;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketAddress;

public class SocketDemo {
   public static void main(String[] args) throws IOException {
      Socket socket = new Socket();  
      InetAddress inetAddress=InetAddress.getByName("localhost");  
      SocketAddress socketAddress=new InetSocketAddress(inetAddress, 6066); 
	  Socket.setSocketImplFactory(null);	  
      socket.bind(socketAddress); 
      socket.setSendBufferSize(1000); 
      System.out.println("SO_SNDBUF: "+socket.getSendBufferSize()); 
      System.out.println("Port number: "+socket.getLocalPort()); 
      System.out.println("Inet Address: "+socket.getInetAddress()); 
      socket.close();
   }
}

Output

Let us compile and run the above program, this will produce the following result −

SO_SNDBUF: 2304
Port number: 6066
Inet Address: null

Example 2

The following example shows the usage of Java Socket setSocketImplFactory() method to set the client socket implementation factory for the application. As first step, we've created a Socket instance using no argument constructor. Here using setSocketImplFactory(), we set as no-op factory implementation. Now, we're printing the SO_SNDBUF value using getSendBufferSize() method. Then we're setting the SO_SNDBUF value as 1000 using setSendBufferSize() method and print the same. In the end, we closed the socket using close() method.

package com.tutorialspoint;

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

public class SocketDemo {
   public static void main(String[] args) throws IOException {
      Socket socket = new Socket();  
	  Socket.setSocketImplFactory(null);
      System.out.println("SO_SNDBUF: "+socket.getSendBufferSize());
      socket.setSendBufferSize(1000);  
      System.out.println("SO_SNDBUF: "+socket.getSendBufferSize());
      socket.close();
   }
}

Output

Let us compile and run the above program, this will produce the following result −

SO_SNDBUF: 8192
SO_SNDBUF: 2304

Example 3

The following example shows the usage of Java Socket setSocketImplFactory() method to set the client socket implementation factory for the application. As first step, we've created a Socket instance using no argument constructor. Using socket.close(), we're closing the socket. Here using setSocketImplFactory(), we set as no-op factory implementation. Now, we're setting the SO_SNDBUF value as 100 using setSendBufferSize() method and then we're printing the SO_SNDBUF flag using getSendBufferSize() method. Then we're setting the SO_SNDBUF value as 1000 using setSendBufferSize() method and print the same. In the end, we closed the socket using close() method. As socket is already closed, setSendBufferSize() method call throws an exception as shown below −

package com.tutorialspoint;

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

public class SocketDemo {
   public static void main(String[] args) throws IOException {
      Socket socket = new Socket();  
      socket.close();	  
      Socket.setSocketImplFactory(null);
      socket.setSendBufferSize(100); 
      System.out.println("SO_SNDBUF: "+socket.getSendBufferSize());
      socket.setSendBufferSize(1000);  
      System.out.println("SO_SNDBUF: "+socket.getSendBufferSize());
      socket.close();
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Exception in thread "main" java.net.SocketException: Socket is closed
	at java.base/java.net.Socket.setSendBufferSize(Socket.java:1213)
	at com.tutorialspoint.SocketDemo.main(SocketDemo.java:11)