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    }