Java HTTP Port Find getAvailablePort(final int basePort)

Description

get Available Port

License

Apache License

Declaration

public static int getAvailablePort(final int basePort) 

Method Source Code

//package com.java2s;
/*//from  ww  w. j av a 2  s  .  c o m
 * 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.
 */

import java.io.IOException;

import java.net.ServerSocket;

import java.util.NoSuchElementException;

public class Main {
    public static int getAvailablePort() {
        try {
            ServerSocket s = new ServerSocket(0);
            s.setReuseAddress(true);
            s.close();
            return s.getLocalPort();
        } catch (IOException e) {
            throw new IllegalStateException("Failed to find an available port", e);
        }
    }

    public static int getAvailablePort(final int basePort) {
        if (basePort == 0) {
            return getAvailablePort();
        }
        if (basePort < 0 || basePort > 65535) {
            throw new IllegalArgumentException("Illegal port number: " + basePort);
        }
        for (int i = basePort; i <= 65535; i++) {
            if (isPortAvailable(i)) {
                return i;
            }
        }
        throw new NoSuchElementException("Could not find available port greater than or equals to " + basePort);
    }

    public static boolean isPortAvailable(final int port) {
        ServerSocket s = null;
        try {
            s = new ServerSocket(port);
            s.setReuseAddress(true);
            return true;
        } catch (IOException e) {
            return false;
        } finally {
            if (s != null) {
                try {
                    s.close();
                } catch (IOException e) {
                    ;
                }
            }
        }
    }
}

Related

1. getAvailablePort()
2. getAvailablePort()
3. getAvailablePort()
4. getAvailablePort()
5. getAvailablePort()
6. getAvailablePort(int defaultPort)
7. getAvailablePort(int port)
8. getAvailablePort(int port)
9. getAvailablePort(int prefferedPort)