Here you can find the source of isUrl(final String url)
public static boolean isUrl(final String url)
//package com.java2s; /******************************************************************************* * Copyright 2014 Federal Chancellery Austria * MOA-ID has been developed in a cooperation between BRZ, the Federal * Chancellery Austria - ICT staff unit, and Graz University of Technology. * * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by * the European Commission - subsequent versions of the EUPL (the "Licence"); * You may not use this work except in compliance with the Licence. * You may obtain a copy of the Licence at: * http://www.osor.eu/eupl//*w ww . j av a 2 s . co m*/ * * Unless required by applicable law or agreed to in writing, software * distributed under the Licence is distributed on an "AS IS" basis, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the Licence for the specific language governing permissions and * limitations under the Licence. * * This product combines work with different licenses. See the "NOTICE" text * file for details on the various modules and licenses. * The "NOTICE" text file is part of the distribution. Any derivative works * that you distribute must include a readable copy of the "NOTICE" text file. *******************************************************************************/ import java.util.regex.Matcher; import java.util.regex.Pattern; public class Main { public static final String REGEX_HTTPS = "^(https?)://[-a-zA-Z0-9+&@#/%?=~_|!:,.;]*[-a-zA-Z0-9+&@#/%=~_|]"; public static final String REGEX_FILE = "^(file):/.[-a-zA-Z0-9+&@#/%?=~_|!:,.;]*[-a-zA-Z0-9+&@#/%=~_|]"; public static boolean isUrl(final String url) { Pattern urlPattern; if (url.startsWith("file")) { urlPattern = Pattern.compile(REGEX_FILE, Pattern.CASE_INSENSITIVE); } else { urlPattern = Pattern.compile(REGEX_HTTPS, Pattern.CASE_INSENSITIVE); } Matcher matcher = urlPattern.matcher(url); return matcher.find(); } }