asked on

closing a socket

I have a very basic question: how can I test a Socket to determine whether or not it is open?

I know I receive an exception if the socket is unexpectedly closed. I also know I receive a known return code (e.g. null) if I read or write to a closed socket. But how do I ask a Socket whether or not it is open without having to read or write?

Thanks!

Joe

evijay

I didnt find any way to do this (as per my knowledge). The best way to handle this is

After you say
InputStream is = socket.getInputStream();
create a push back input stream
PushbackInputStream ps = new PushBackInputStream (ps);

use ps instead of is to read data from socket.

Write an utility routine to test for socket closure as below

public static boolean isSocketClosed(PushbackInputStream pInpStr) throws Exception
{
int rd;
try { rd = pInpStr.read(); } catch (Exception e) { System.out.println("Socket closed !!"); return true; }
System.out.println("not yet closed!!");
pInpStr.unread(rd);
return false;
}

Charmaine041198

Do you mean to test if a socket is still valid?

eg.
// start

Socket mysocket = new Socket(hostname,portnum);

// Test if socket is valid
if(mysocket = null) {
// socket closed, do something
} else {
// socket open, read or write using socket
}

// end

ASKER CERTIFIED SOLUTION

evijay

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial