Here you can find the source of getHostNameReliably(final String requestingHost, final InetAddress site, final URL requestingUrl)
public static String getHostNameReliably(final String requestingHost, final InetAddress site, final URL requestingUrl)
//package com.java2s; /*/*from w w w . ja v a 2 s .c o m*/ * Copyright 2000-2013 JetBrains s.r.o. * * Licensed 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.net.*; public class Main { public static String getHostNameReliably(final String requestingHost, final InetAddress site, final URL requestingUrl) { String host = requestingHost; if (host == null) { if (site != null) { host = site.getHostName(); } else if (requestingUrl != null) { host = requestingUrl.getHost(); } } host = host == null ? "" : host; return host; } }