/*******************************************************************************
* Copyright (c) 2015 Pivotal, Inc.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Pivotal, Inc. - initial API and implementation
*******************************************************************************/
package org.springframework.ide.eclipse.boot.launch.util;
import java.io.IOException;
import java.net.ServerSocket;
import java.util.HashSet;
/**
* @author Kris De Volder
*/
public class PortFinder {
/**
* If you only need the one port you can use this. No need to instantiate the class
*/
public static int findFreePort() throws IOException {
ServerSocket socket = new ServerSocket(0);
try {
return socket.getLocalPort();
} finally {
try {
socket.close();
} catch (IOException e) {
}
}
}
private HashSet<Integer> used = new HashSet<Integer>();
/**
* Finds a port that is currently free and is guaranteed to be different from any of the
* port numbers previously returned by this PortFinder instance.
*/
public synchronized int findUniqueFreePort() throws IOException {
int port;
do {
port = findFreePort();
} while (used.contains(port));
used.add(port);
return port;
}
}