1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.vfs2.filter; 18 19 import java.io.Serializable; 20 21 import org.apache.commons.vfs2.FileFilter; 22 import org.apache.commons.vfs2.FileSelectInfo; 23 import org.apache.commons.vfs2.FileSystemException; 24 25 /** 26 * This filter accepts {@code File}s that are symbolic links. 27 * <p> 28 * Example, showing how to print out a list of the current directory's 29 * <i>symbolic link</i> files: 30 * </p> 31 * 32 * <pre> 33 * FileSystemManager fsManager = VFS.getManager(); 34 * FileObject dir = fsManager.toFileObject(new File(".")); 35 * FileObject[] files = dir.findFiles(new FileFilterSelector(SymbolicLinkFileFilter.SYMBOLIC)); 36 * for (int i = 0; i < files.length; i++) { 37 * System.out.println(files[i]); 38 * } 39 * </pre> 40 * 41 * <p> 42 * Example, showing how to print out a list of the current directory's 43 * <i>actual</i> (i.e. symbolic link) files: 44 * </p> 45 * 46 * <pre> 47 * FileSystemManager fsManager = VFS.getManager(); 48 * FileObject dir = fsManager.toFileObject(new File(".")); 49 * FileObject[] files = dir.findFiles(new FileFilterSelector(SymbolicLinkFileFilter.ACTUAL)); 50 * for (int i = 0; i < files.length; i++) { 51 * System.out.println(files[i]); 52 * } 53 * </pre> 54 * 55 * @since 2.4 56 */ 57 public class SymbolicLinkFileFilter implements FileFilter, Serializable { 58 59 private static final long serialVersionUID = 1L; 60 61 /** Singleton instance of <i>hidden</i> filter. */ 62 public static final FileFilter SYMBOLIC = new SymbolicLinkFileFilter(); 63 64 /** Singleton instance of <i>visible</i> filter. */ 65 public static final FileFilter ACTUAL = new NotFileFilter(SYMBOLIC); 66 67 /** 68 * Restrictive constructor. 69 */ 70 protected SymbolicLinkFileFilter() { 71 } 72 73 /** 74 * Checks to see if the file is a symbolic link. Non existing files won't be accepted. 75 * 76 * @param fileSelectInfo the file to check 77 * 78 * @return {@code true} if the file is <i>symbolic link</i>, otherwise {@code false}. 79 * @throws FileSystemException Thrown for file system errors. 80 */ 81 @Override 82 public boolean accept(final FileSelectInfo fileSelectInfo) throws FileSystemException { 83 if (!fileSelectInfo.getFile().exists()) { 84 return false; 85 } 86 return fileSelectInfo.getFile().isSymbolicLink(); 87 } 88 89 }