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. */ package org.apache.commons.vfs2; import java.util.Arrays; import java.util.Collection; import java.util.HashSet; import java.util.Set; /** * A {@link FileSelector} that selects based on file extensions. * <p> * The extension comparison is case insensitive. * </p> * <p> * The selector makes a copy of a given Collection or array. Changing the object passed in the constructors will not * affect the selector. * </p> * * @since 2.1 */ public class FileExtensionSelector implements FileSelector { /** * The extensions to select. */ private final Set<String> extensions = new HashSet<String>(); /** * Creates a new selector for the given extensions. * * @param extensions * The extensions to be included by this selector. */ public FileExtensionSelector(final Collection<String> extensions) { if (extensions != null) { this.extensions.addAll(extensions); } } /** * Creates a new selector for the given extensions. * * @param extensions * The extensions to be included by this selector. */ public FileExtensionSelector(final String... extensions) { if (extensions != null) { this.extensions.addAll(Arrays.asList(extensions)); } } /** * Determines if a file or folder should be selected. * * @param fileInfo * The file selection information. * @return true if the file should be selected, false otherwise. */ @Override public boolean includeFile(final FileSelectInfo fileInfo) { if (this.extensions == null) { return false; } for (final String extension : this.extensions) { if (fileInfo.getFile().getName().getExtension().equalsIgnoreCase(extension)) { return true; } } return false; } /** * Determines whether a folder should be traversed. * * @param fileInfo * The file selection information. * @return true if descendants should be traversed, fase otherwise. */ @Override public boolean traverseDescendents(final FileSelectInfo fileInfo) { return true; } }