CanReadFileFilter.java
- /*
- * 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.io.filefilter;
- import java.io.File;
- import java.io.Serializable;
- import java.nio.file.FileVisitResult;
- import java.nio.file.Files;
- import java.nio.file.Path;
- import java.nio.file.attribute.BasicFileAttributes;
- /**
- * This filter accepts {@link File}s that can be read.
- * <p>
- * Example, showing how to print out a list of the current directory's <em>readable</em> files:
- * </p>
- * <h2>Using Classic IO</h2>
- * <pre>
- * File dir = FileUtils.current();
- * String[] files = dir.list(CanReadFileFilter.CAN_READ);
- * for (String file : files) {
- * System.out.println(file);
- * }
- * </pre>
- *
- * <p>
- * Example, showing how to print out a list of the current directory's <em>un-readable</em> files:
- *
- * <pre>
- * File dir = FileUtils.current();
- * String[] files = dir.list(CanReadFileFilter.CANNOT_READ);
- * for (String file : files) {
- * System.out.println(file);
- * }
- * </pre>
- *
- * <p>
- * Example, showing how to print out a list of the current directory's <em>read-only</em> files:
- *
- * <pre>
- * File dir = FileUtils.current();
- * String[] files = dir.list(CanReadFileFilter.READ_ONLY);
- * for (String file : files) {
- * System.out.println(file);
- * }
- * </pre>
- * <h2>Deprecating Serialization</h2>
- * <p>
- * <em>Serialization is deprecated and will be removed in 3.0.</em>
- * </p>
- *
- * @since 1.3
- */
- public class CanReadFileFilter extends AbstractFileFilter implements Serializable {
- /** Singleton instance of <em>readable</em> filter */
- public static final IOFileFilter CAN_READ = new CanReadFileFilter();
- /** Singleton instance of not <em>readable</em> filter */
- public static final IOFileFilter CANNOT_READ = CAN_READ.negate();
- /** Singleton instance of <em>read-only</em> filter */
- public static final IOFileFilter READ_ONLY = CAN_READ.and(CanWriteFileFilter.CANNOT_WRITE);
- private static final long serialVersionUID = 3179904805251622989L;
- /**
- * Restrictive constructor.
- */
- protected CanReadFileFilter() {
- }
- /**
- * Checks to see if the file can be read.
- *
- * @param file the File to check.
- * @return {@code true} if the file can be read, otherwise {@code false}.
- */
- @Override
- public boolean accept(final File file) {
- return file != null && file.canRead();
- }
- /**
- * Checks to see if the file can be read.
- *
- * @param file the File to check.
- * @param attributes the path's basic attributes (may be null).
- * @return {@code true} if the file can be read, otherwise {@code false}.
- * @since 2.9.0
- */
- @Override
- public FileVisitResult accept(final Path file, final BasicFileAttributes attributes) {
- return toFileVisitResult(file != null && Files.isReadable(file));
- }
- }