Setting a timeout for socket operations

Question

When I create a socket:

Socket socket = new Socket(ipAddress, port); 

It throws an exception, which is OK, because the IP address is not available. (The test variables where String ipAddress = "192.168.0.3" and int port = 300.)

The problem is: how do I set it to timeout for that socket?

When I create the socket, how do I reduce the time before I get a UnknownHostException and get the socket to timeout?

Answer 1

Use the Socket() constructor, and connect(SocketAddress endpoint, int timeout) method instead.

In your case it would look something like:

Socket socket = new Socket(); socket.connect(new InetSocketAddress(ipAddress, port), 1000); 

---

Quoting from the documentation

connect

public void connect(SocketAddress endpoint, int timeout) throws IOException 

Connects this socket to the server with a specified timeout value. A timeout of zero is interpreted as an infinite timeout. The connection will then block until established or an error occurs.

Parameters:

endpoint - the SocketAddress
timeout - the timeout value to be used in milliseconds.

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

Since: 1.4

Answer 2

You don't set a timeout for the socket, you set a timeout for the operations you perform on that socket.

For example socket.connect(otherAddress, timeout)

Or socket.setSoTimeout(timeout) for setting a timeout on read() operations.

See: http://docs.oracle.com/javase/7/docs/api/java/net/Socket.html