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Diffstat (limited to 'src/main/java/org/apache/commons/io/FileDeleteStrategy.java')
-rw-r--r-- | src/main/java/org/apache/commons/io/FileDeleteStrategy.java | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/io/FileDeleteStrategy.java b/src/main/java/org/apache/commons/io/FileDeleteStrategy.java new file mode 100644 index 00000000..6bc51076 --- /dev/null +++ b/src/main/java/org/apache/commons/io/FileDeleteStrategy.java @@ -0,0 +1,161 @@ +/* + * 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; + +import java.io.File; +import java.io.IOException; + +/** + * Strategy for deleting files. + * <p> + * There is more than one way to delete a file. + * You may want to limit access to certain directories, to only delete + * directories if they are empty, or maybe to force deletion. + * </p> + * <p> + * This class captures the strategy to use and is designed for user subclassing. + * </p> + * + * @since 1.3 + */ +public class FileDeleteStrategy { + + /** + * Force file deletion strategy. + */ + static class ForceFileDeleteStrategy extends FileDeleteStrategy { + /** Default Constructor */ + ForceFileDeleteStrategy() { + super("Force"); + } + + /** + * Deletes the file object. + * <p> + * This implementation uses {@code FileUtils.forceDelete()} + * if the file exists. + * </p> + * + * @param fileToDelete the file to delete, not null + * @return Always returns {@code true} + * @throws NullPointerException if the file is null + * @throws IOException if an error occurs during file deletion + */ + @Override + protected boolean doDelete(final File fileToDelete) throws IOException { + FileUtils.forceDelete(fileToDelete); + return true; + } + } + + /** + * The singleton instance for normal file deletion, which does not permit + * the deletion of directories that are not empty. + */ + public static final FileDeleteStrategy NORMAL = new FileDeleteStrategy("Normal"); + + /** + * The singleton instance for forced file deletion, which always deletes, + * even if the file represents a non-empty directory. + */ + public static final FileDeleteStrategy FORCE = new ForceFileDeleteStrategy(); + + /** The name of the strategy. */ + private final String name; + + /** + * Restricted constructor. + * + * @param name the name by which the strategy is known + */ + protected FileDeleteStrategy(final String name) { + this.name = name; + } + + /** + * Deletes the file object, which may be a file or a directory. + * If the file does not exist, the method just returns. + * <p> + * Subclass writers should override {@link #doDelete(File)}, not this method. + * </p> + * + * @param fileToDelete the file to delete, not null + * @throws NullPointerException if the file is null + * @throws IOException if an error occurs during file deletion + */ + public void delete(final File fileToDelete) throws IOException { + if (fileToDelete.exists() && !doDelete(fileToDelete)) { + throw new IOException("Deletion failed: " + fileToDelete); + } + } + + /** + * Deletes the file object, which may be a file or a directory. + * All {@link IOException}s are caught and false returned instead. + * If the file does not exist or is null, true is returned. + * <p> + * Subclass writers should override {@link #doDelete(File)}, not this method. + * </p> + * + * @param fileToDelete the file to delete, null returns true + * @return true if the file was deleted, or there was no such file + */ + public boolean deleteQuietly(final File fileToDelete) { + if (fileToDelete == null || !fileToDelete.exists()) { + return true; + } + try { + return doDelete(fileToDelete); + } catch (final IOException ex) { + return false; + } + } + + /** + * Actually deletes the file object, which may be a file or a directory. + * <p> + * This method is designed for subclasses to override. + * The implementation may return either false or an {@link IOException} + * when deletion fails. The {@link #delete(File)} and {@link #deleteQuietly(File)} + * methods will handle either response appropriately. + * A check has been made to ensure that the file will exist. + * </p> + * <p> + * This implementation uses {@link FileUtils#delete(File)}. + * </p> + * + * @param file the file to delete, exists, not null + * @return true if the file was deleted + * @throws NullPointerException if the file is null + * @throws IOException if an error occurs during file deletion + */ + protected boolean doDelete(final File file) throws IOException { + FileUtils.delete(file); + return true; + } + + /** + * Gets a string describing the delete strategy. + * + * @return a string describing the delete strategy + */ + @Override + public String toString() { + return "FileDeleteStrategy[" + name + "]"; + } + +} |