001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019 package org.apache.hadoop.fs;
020
021 import java.util.regex.PatternSyntaxException;
022 import java.io.IOException;
023
024 import org.apache.hadoop.classification.InterfaceAudience;
025 import org.apache.hadoop.classification.InterfaceStability;
026
027 /**
028 * A filter for POSIX glob pattern with brace expansions.
029 */
030 @InterfaceAudience.Public
031 @InterfaceStability.Evolving
032 public class GlobFilter implements PathFilter {
033 private final static PathFilter DEFAULT_FILTER = new PathFilter() {
034 public boolean accept(Path file) {
035 return true;
036 }
037 };
038
039 private PathFilter userFilter = DEFAULT_FILTER;
040 private GlobPattern pattern;
041
042 /**
043 * Creates a glob filter with the specified file pattern.
044 *
045 * @param filePattern the file pattern.
046 * @throws IOException thrown if the file pattern is incorrect.
047 */
048 public GlobFilter(String filePattern) throws IOException {
049 init(filePattern, DEFAULT_FILTER);
050 }
051
052 /**
053 * Creates a glob filter with the specified file pattern and an user filter.
054 *
055 * @param filePattern the file pattern.
056 * @param filter user filter in addition to the glob pattern.
057 * @throws IOException thrown if the file pattern is incorrect.
058 */
059 public GlobFilter(String filePattern, PathFilter filter) throws IOException {
060 init(filePattern, filter);
061 }
062
063 void init(String filePattern, PathFilter filter) throws IOException {
064 try {
065 userFilter = filter;
066 pattern = new GlobPattern(filePattern);
067 }
068 catch (PatternSyntaxException e) {
069 // Existing code expects IOException startWith("Illegal file pattern")
070 throw new IOException("Illegal file pattern: "+ e.getMessage(), e);
071 }
072 }
073
074 boolean hasPattern() {
075 return pattern.hasWildcard();
076 }
077
078 public boolean accept(Path path) {
079 return pattern.matches(path.getName()) && userFilter.accept(path);
080 }
081 }