Java Socket connect() method

25 Mar 2025 | 3 min read

connect(SocketAddress endpoint)

The connect() method of Java Socket class connects the specified socket to the server.

Syntax

Parameter

The parameter 'endpoint' represents the SocketAddress.

Return

NA

Throws

IOException - if an error occurs during the connection.

IllegalBlockingModeException - if this socket has an associated channel and the channel is in non-blocking mode.

IllegalArgumentException - if the specified endpoint is null or if the SocketAddress subclass not supported by this socket.

Example 1

Output:

 Inet address: localhost/127.0.0.1 Port number: 1085 

Example 2

Output:

 Exception in thread "main" java.lang.IllegalArgumentException: port out of range:-1085	at java.net.InetSocketAddress.checkPort(InetSocketAddress.java:143)	at java.net.InetSocketAddress.(InetSocketAddress.java:188)	at com.tpointtech.JavaSocketConnectExample2.main(JavaSocketConnectExample2.java:13) 

Example 3

Output:

 Exception in thread "main" java.lang.IllegalArgumentException: connect: The address can't be null	at java.net.Socket.connect(Socket.java:560)	at java.net.Socket.connect(Socket.java:538)	at com.tpointtech.JavaSocketConnectExample3.main(JavaSocketConnectExample3.java:13) 

connect(SocketAddress endpoint, int timeout)

The connect() method of Java Socket class connects this socket to the server with the given timeout value. A zero timeout is inferred as an infinite timeout.

Syntax

Parameter

endpoint - it represents the SocketAddress.

timeout - it represents the timeout value to be used in milliseconds.

Return

NA

Throws

IOException - if an error occurs during the connection.

SocketTimeoutException - if timeout expires before connecting.

IllegalBlockingModeException - if this socket has an associated channel and the channel is in non-blocking mode.

IllegalArgumentException - if endpoint is null or is a SocketAddress subclass not supported by this socket.

Example 1

Output:

 Inet address: localhost/127.0.0.1 Port number: 1085 

Example 2

Output:

 Exception in thread "main" java.lang.IllegalArgumentException: connect: timeout can't be negative	at java.net.Socket.connect(Socket.java:563)	at com.tpointtech.JavaSocketConnectExample5.main(JavaSocketConnectExample5.java:19)