Java tutorial
/** * 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.net.MalformedURLException; import java.net.URL; import java.util.ArrayList; import java.util.List; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Utils { public static String getFirstNotEmpty(List<String> list) { if (isEmpty(list)) { return null; } for (String item : list) { if (!isEmpty(item)) { return item; } } return null; } public static List<String> getFound(String contents, String regex) { if (isEmpty(regex) || isEmpty(contents)) { return null; } List<String> results = new ArrayList<String>(); Pattern pattern = Pattern.compile(regex, Pattern.UNICODE_CASE); Matcher matcher = pattern.matcher(contents); while (matcher.find()) { if (matcher.groupCount() > 0) { results.add(matcher.group(1)); } else { results.add(matcher.group()); } } return results; } public static boolean isEmpty(List<String> list) { if (list == null || list.size() == 0) { return true; } if (list.size() == 1 && isEmpty(list.get(0))) { return true; } return false; } public static boolean isEmpty(String str) { if (str != null && str.trim().length() > 0) { return false; } return true; } }