Java - Socket setSoTimeout(int timeout) Method

Description

The Java Socket setSoTimeout(int timeout) is used to enable/disable SO_TIMEOUT with the given timeout, in milliseconds. For a non-zero timeout, a read() call on the InputStream associated with this Socket will be a blocking call for only this amount of time. In case timeout expires, a java.net.SocketTimeoutException is raised, although the Socket is still valid. The option must be enabled prior to entering the blocking operation to have effect. The timeout must always be greater than 0. A zero timeout is interpreted as an infinite timeout.

Declaration

Following is the declaration for java.net.Socket.setSoTimeout(int timeout) method.

public void setSoTimeout(int timeout) throws SocketException

Parameters

timeout − the specified timeout, in milliseconds.

Return Value

N/A

Exception

SocketException − if there is an error in the underlying protocol, such as a TCP error.

Example 1

The following example shows the usage of Java Socket setSoTimeout() method to set the value of the SO_TIMEOUT option of socket instance. 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. Using InetSocketAddress object, we've created a SocketAddress object and then using bind() method, we bind the address to the socket. Using setSoTimeout(), we're setting the value of the SO_TIMEOUT option as 1000. Once done, we're printing the SO_TIMEOUT value using getSoTimeout() 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.bind(socketAddress); 
      socket.setSoTimeout(1000);
      System.out.println("SO_TIMEOUT: "+socket.getSoTimeout()); 
      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_TIMEOUT: 1000
Port number: 6066
Inet Address: null

Example 2

The following example shows the usage of Java Socket setSoTimeout() method to set the value of SO_TIMEOUT of socket instance. As first step, we've created a Socket instance using no argument constructor. Now, we're printing the SO_TIMEOUT value using getSoTimeout() method. Then we're setting the SO_TIMEOUT value as 1 using setSoTimeout() 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();  

      System.out.println("SO_TIMEOUT: "+socket.getSoTimeout());
      socket.setSoTimeout(1000);  
      System.out.println("SO_TIMEOUT: "+socket.getSoTimeout());
      socket.close();
   }
}

Output

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

SO_TIMEOUT: 0
SO_TIMEOUT: 1000

Example 3

The following example shows the usage of Java Socket setSoTimeout() method to set the value of SO_TIMEOUT of socket instance, if socket is already closed. As first step, we've created a Socket instance using no argument constructor. Using socket.close(), we're closing the socket. Now, we're printing the SO_TIMEOUT flag using getSoTimeout() method. Then we're setting the SO_TIMEOUT value as 1000 using setSoTimeout() method and print the same. In the end, we closed the socket using close() method. As socket is already closed, getSoTimeout() 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();	  

      System.out.println("SO_TIMEOUT: "+socket.getSoTimeout());
      socket.setSoTimeout(1000);  
      System.out.println("SO_TIMEOUT: "+socket.getSoTimeout());
      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.getSoTimeout(Socket.java:1174)
	at com.tutorialspoint.SocketDemo.main(SocketDemo.java:11)