content: /*
   * 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.cassandra.net;
  
  import java.io.IOException;
  import java.net.InetAddress;
  import java.net.ServerSocket;
  import java.net.UnknownHostException;
  
  public class SocketUtils
  {
      /**
       * Returns an available port for the given {@code bindAddress}. When an {@link IOException} occurs when opening a
       * socket or if a {@link SecurityException} is raised because a manager exists and its checkListen method does
       * not allow the operation, the {@code fallbackPort} is returned.
       *
       * @param bindAddress  the ip address for the interface where we need an available port number
       * @param fallbackPort a port to return in case {@link SecurityException} or {@link IOException} is encountered
       * @return an available port the given {@code bindAddress} when succeeds, otherwise the {@code fallbackPort}
       * @throws RuntimeException if no IP address for the {@code bindAddress} could be found
       */
      public static synchronized int findAvailablePort(String bindAddress, int fallbackPort) throws RuntimeException
      {
          try
          {
              return findAvailablePort(InetAddress.getByName(bindAddress), fallbackPort);
          }
          catch (UnknownHostException e)
          {
              throw new RuntimeException(e);
          }
      }
  
      /**
       * Returns an available port for the given {@code bindAddress}. When an {@link IOException} occurs when opening a
       * socket or if a {@link SecurityException} is raised because a manager exists and its checkListen method does
       * not allow the operation, the {@code fallbackPort} is returned.
       *
       * @param bindAddress  the ip address for the interface where we need an available port number
       * @param fallbackPort a port to return in case {@link SecurityException} or {@link IOException} is encountered
       * @return an available port the given {@code bindAddress} when succeeds, otherwise the {@code fallbackPort}
       */
      public static synchronized int findAvailablePort(InetAddress bindAddress, int fallbackPort)
      {
          try (ServerSocket socket = new ServerSocket(0, 50, bindAddress))
          {
              return socket.getLocalPort();
          }
          catch (SecurityException | IOException exception)
          {
              return fallbackPort;
          }
      }
  }
  