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.io.filefilter; 18 19 import java.io.File; 20 21 /** 22 * This filter accepts <code>File</code>s that are directories. 23 * <p> 24 * For example, here is how to print out a list of the 25 * current directory's subdirectories: 26 * 27 * <pre> 28 * File dir = new File("."); 29 * String[] files = dir.list( DirectoryFileFilter.INSTANCE ); 30 * for ( int i = 0; i < files.length; i++ ) { 31 * System.out.println(files[i]); 32 * } 33 * </pre> 34 * 35 * @since Commons IO 1.0 36 * @version $Revision: 471628 $ $Date: 2006-11-06 05:06:45 +0100 (Mo, 06 Nov 2006) $ 37 * 38 * @author Stephen Colebourne 39 * @author Peter Donald 40 */ 41 public class DirectoryFileFilter extends AbstractFileFilter { 42 43 /** 44 * Singleton instance of directory filter. 45 * @since Commons IO 1.3 46 */ 47 public static final IOFileFilter DIRECTORY = new DirectoryFileFilter(); 48 /** 49 * Singleton instance of directory filter. 50 * Please use the identical DirectoryFileFilter.DIRECTORY constant. 51 * The new name is more JDK 1.5 friendly as it doesn't clash with other 52 * values when using static imports. 53 */ 54 public static final IOFileFilter INSTANCE = DIRECTORY; 55 56 /** 57 * Restrictive consructor. 58 */ 59 protected DirectoryFileFilter() { 60 } 61 62 /** 63 * Checks to see if the file is a directory. 64 * 65 * @param file the File to check 66 * @return true if the file is a directory 67 */ 68 public boolean accept(File file) { 69 return file.isDirectory(); 70 } 71 72 }