| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| * |
| */ |
| package org.apache.asyncweb.common.integration; |
| |
| import java.io.IOException; |
| import java.net.DatagramSocket; |
| import java.net.ServerSocket; |
| import java.util.NoSuchElementException; |
| import java.util.Set; |
| import java.util.TreeSet; |
| |
| /** |
| * Finds currently available server ports. |
| * |
| * @author The Apache MINA Project (dev@mina.apache.org) |
| * @version $Rev$ |
| * @see <a href="http://www.iana.org/assignments/port-numbers">IANA.org</a> |
| */ |
| public class AvailablePortFinder { |
| /** |
| * The minimum number of server port number. |
| */ |
| public static final int MIN_PORT_NUMBER = 1; |
| |
| /** |
| * The maximum number of server port number. |
| */ |
| public static final int MAX_PORT_NUMBER = 49151; |
| |
| /** |
| * Creates a new instance. |
| */ |
| private AvailablePortFinder() { |
| } |
| |
| /** |
| * Returns the {@link Set} of currently available port numbers |
| * ({@link Integer}). This method is identical to |
| * <code>getAvailablePorts(MIN_PORT_NUMBER, MAX_PORT_NUMBER)</code>. |
| * |
| * WARNING: this can take a very long time. |
| */ |
| public static Set<Integer> getAvailablePorts() { |
| return getAvailablePorts(MIN_PORT_NUMBER, MAX_PORT_NUMBER); |
| } |
| |
| /** |
| * Gets the next available port starting at the lowest port number. |
| * |
| * @throws NoSuchElementException if there are no ports available |
| */ |
| public static int getNextAvailable() { |
| return getNextAvailable(MIN_PORT_NUMBER); |
| } |
| |
| /** |
| * Gets the next available port starting at a port. |
| * |
| * @param fromPort the port to scan for availability |
| * @throws NoSuchElementException if there are no ports available |
| */ |
| public static int getNextAvailable(int fromPort) { |
| if (fromPort < MIN_PORT_NUMBER || fromPort > MAX_PORT_NUMBER) { |
| throw new IllegalArgumentException("Invalid start port: " |
| + fromPort); |
| } |
| |
| for (int i = fromPort; i <= MAX_PORT_NUMBER; i++) { |
| if (available(i)) { |
| return i; |
| } |
| } |
| |
| throw new NoSuchElementException("Could not find an available port " |
| + "above " + fromPort); |
| } |
| |
| /** |
| * Checks to see if a specific port is available. |
| * |
| * @param port the port to check for availability |
| */ |
| public static boolean available(int port) { |
| if (port < MIN_PORT_NUMBER || port > MAX_PORT_NUMBER) { |
| throw new IllegalArgumentException("Invalid start port: " + port); |
| } |
| |
| ServerSocket ss = null; |
| DatagramSocket ds = null; |
| try { |
| ss = new ServerSocket(port); |
| ss.setReuseAddress(true); |
| ds = new DatagramSocket(port); |
| ds.setReuseAddress(true); |
| return true; |
| } catch (IOException e) { |
| } finally { |
| if (ds != null) { |
| ds.close(); |
| } |
| |
| if (ss != null) { |
| try { |
| ss.close(); |
| } catch (IOException e) { |
| /* should not be thrown */ |
| } |
| } |
| } |
| |
| return false; |
| } |
| |
| /** |
| * Returns the {@link Set} of currently avaliable port numbers ({@link Integer}) |
| * between the specified port range. |
| * |
| * @throws IllegalArgumentException if port range is not between |
| * {@link #MIN_PORT_NUMBER} and {@link #MAX_PORT_NUMBER} or |
| * <code>fromPort</code> if greater than <code>toPort</code>. |
| */ |
| public static Set<Integer> getAvailablePorts(int fromPort, int toPort) { |
| if (fromPort < MIN_PORT_NUMBER || toPort > MAX_PORT_NUMBER |
| || fromPort > toPort) { |
| throw new IllegalArgumentException("Invalid port range: " |
| + fromPort + " ~ " + toPort); |
| } |
| |
| Set<Integer> result = new TreeSet<Integer>(); |
| |
| for (int i = fromPort; i <= toPort; i++) { |
| ServerSocket s = null; |
| |
| try { |
| s = new ServerSocket(i); |
| result.add(new Integer(i)); |
| } catch (IOException e) { |
| } finally { |
| if (s != null) { |
| try { |
| s.close(); |
| } catch (IOException e) { |
| /* should not be thrown */ |
| } |
| } |
| } |
| } |
| |
| return result; |
| } |
| } |