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.io.filefilter;
018
019import java.io.File;
020import java.io.Serializable;
021import java.nio.file.FileVisitResult;
022import java.nio.file.Path;
023import java.nio.file.attribute.BasicFileAttributes;
024
025/**
026 * A file filter that always returns true.
027 * <h2>Deprecating Serialization</h2>
028 * <p>
029 * <em>Serialization is deprecated and will be removed in 3.0.</em>
030 * </p>
031 *
032 * @since 1.0
033 * @see FileFilterUtils#trueFileFilter()
034 */
035public class TrueFileFilter implements IOFileFilter, Serializable {
036
037    private static final String TO_STRING = Boolean.TRUE.toString();
038
039    private static final long serialVersionUID = 8782512160909720199L;
040
041    /**
042     * Singleton instance of true filter.
043     *
044     * @since 1.3
045     */
046    public static final IOFileFilter TRUE = new TrueFileFilter();
047
048    /**
049     * Singleton instance of true filter. Please use the identical TrueFileFilter.TRUE constant. The new name is more
050     * JDK 1.5 friendly as it doesn't clash with other values when using static imports.
051     */
052    public static final IOFileFilter INSTANCE = TRUE;
053
054    /**
055     * Restrictive constructor.
056     */
057    protected TrueFileFilter() {
058    }
059
060    /**
061     * Returns true.
062     *
063     * @param file the file to check (ignored)
064     * @return true
065     */
066    @Override
067    public boolean accept(final File file) {
068        return true;
069    }
070
071    /**
072     * Returns true.
073     *
074     * @param dir the directory to check (ignored)
075     * @param name the file name (ignored)
076     * @return true
077     */
078    @Override
079    public boolean accept(final File dir, final String name) {
080        return true;
081    }
082
083    /**
084     * Returns true.
085     * @param file the file to check (ignored)
086     *
087     * @return true
088     * @since 2.9.0
089     */
090    @Override
091    public FileVisitResult accept(final Path file, final BasicFileAttributes attributes) {
092        return FileVisitResult.CONTINUE;
093    }
094
095    @Override
096    public IOFileFilter and(final IOFileFilter fileFilter) {
097        // TRUE AND expression <=> expression
098        return fileFilter;
099    }
100
101    @Override
102    public IOFileFilter negate() {
103        return FalseFileFilter.INSTANCE;
104    }
105
106    @Override
107    public IOFileFilter or(final IOFileFilter fileFilter) {
108        // TRUE OR expression <=> true
109        return INSTANCE;
110    }
111
112    @Override
113    public String toString() {
114        return TO_STRING;
115    }
116}