Java HTTP Port Find getFreePort()

Description

Uses Minas AvailablePortFinder to find a port, starting at 14000.

License

Apache License

Return

a free port.

Declaration

public static int getFreePort() 

Method Source Code

//package com.java2s;
/**// ww w. ja  v  a2  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.DatagramSocket;

import java.net.ServerSocket;

public class Main {
    public static final int MAX_PORT_NUMBER = 65535;

    /**
     * Uses Minas AvailablePortFinder to find a port, starting at 14000.
     * 
     * @return a free port.
     */
    public static int getFreePort() {
        int startPort = 14000;
        return getFreePort(startPort);
    }

    /**
     * Uses Minas AvailablePortFinder to find a port, starting at startPort.
     * 
     * @return a free port.
     */
    public static int getFreePort(int pStartPort) {
        int startPort = pStartPort;
        while (!available(startPort)) {
            startPort++;
        }
        return startPort;
    }

    /**
     * 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 < 1000 || 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;
    }
}

Related

1. getCorrectHostnamePort(String hostPort)
2. getEffectivePort(String scheme, int specifiedPort)
3. getEphemeralPort()
4. getFreeLocalPort()
5. getFreePort()
6. getFreePort()
7. getFreePort()
8. getFreePort()
9. getFreePort()