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.activemq.util;
  
  import java.net.InetAddress;
  import java.net.UnknownHostException;
  
  public class InetAddressUtil {
  
  	/**
  	 * When using the {@link java.net.InetAddress#getHostName()} method in an 
  	 * environment where neither a proper DNS lookup nor an <tt>/etc/hosts</tt> 
  	 * entry exists for a given host, the following exception will be thrown: 
  	 * <code>
  	 * java.net.UnknownHostException: &lt;hostname&gt;: &lt;hostname&gt;
       *  at java.net.InetAddress.getLocalHost(InetAddress.java:1425)
       *   ...
  	 * </code>
  	 * Instead of just throwing an UnknownHostException and giving up, this 
  	 * method grabs a suitable hostname from the exception and prevents the 
  	 * exception from being thrown. If a suitable hostname cannot be acquired
  	 * from the exception, only then is the <tt>UnknownHostException</tt> thrown. 
  	 * 
  	 * @return The hostname 
  	 * @throws UnknownHostException
  	 * @see {@link java.net.InetAddress#getLocalHost()}
  	 * @see {@link java.net.InetAddress#getHostName()}
  	 */
  	public static String getLocalHostName() throws UnknownHostException {
  		try {
  			return (InetAddress.getLocalHost()).getHostName();
  		} catch (UnknownHostException uhe) {
  			String host = uhe.getMessage(); // host = "hostname: hostname"
  			if (host != null) {
  				int colon = host.indexOf(':');
  				if (colon > 0) {
  					return host.substring(0, colon);
  				}
  			}
  			throw uhe;
  		}
  	}
  }
  