001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.vfs2.filter; 018 019import java.io.Serializable; 020 021import org.apache.commons.vfs2.FileFilter; 022import org.apache.commons.vfs2.FileSelectInfo; 023import org.apache.commons.vfs2.FileSystemException; 024import org.apache.commons.vfs2.FileType; 025 026/** 027 * This filter accepts {@code File}s that are directories. 028 * <p> 029 * For example, here is how to print out a list of the current directory's sub 030 * directories: 031 * </p> 032 * 033 * <pre> 034 * FileSystemManager fsManager = VFS.getManager(); 035 * FileObject dir = fsManager.toFileObject(new File(".")); 036 * FileObject[] files = dir.findFiles(new FileFilterSelector(DirectoryFileFilter.DIRECTORY)); 037 * for (int i = 0; i < files.length; i++) { 038 * System.out.println(files[i]); 039 * } 040 * </pre> 041 * 042 * @author This code was originally ported from Apache Commons IO File Filter 043 * @see "https://commons.apache.org/proper/commons-io/" 044 * @since 2.4 045 */ 046public class DirectoryFileFilter implements FileFilter, Serializable { 047 048 /** 049 * Singleton instance of directory filter. 050 */ 051 public static final FileFilter DIRECTORY = new DirectoryFileFilter(); 052 053 private static final long serialVersionUID = 1L; 054 055 /** 056 * Restrictive constructor. 057 */ 058 protected DirectoryFileFilter() { 059 } 060 061 /** 062 * Checks to see if the file is a directory. 063 * 064 * @param fileSelectInfo the File to check 065 * @return {@code true} if the file is a directory 066 * @throws FileSystemException Thrown for file system errors. 067 */ 068 @Override 069 public boolean accept(final FileSelectInfo fileSelectInfo) throws FileSystemException { 070 return fileSelectInfo.getFile().getType() == FileType.FOLDER; 071 } 072 073}