HadoopFSUtil.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.nutch.util;

import java.io.IOException;

import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.PathFilter;

public class HadoopFSUtil {

    /**
     * Returns PathFilter that passes all paths through.
     */
    public static PathFilter getPassAllFilter() {
        return new PathFilter() {
            public boolean accept(Path arg0) {
                return true;
            }
        };
    }

    /**
     * Returns PathFilter that passes directories through.
     */
    public static PathFilter getPassDirectoriesFilter(final FileSystem fs) {
        return new PathFilter() {
            public boolean accept(final Path path) {
                try {
                    return fs.getFileStatus(path).isDir();
                } catch (IOException ioe) {
                    return false;
                }
            }

        };
    }
    
    /**
     * Turns an array of FileStatus into an array of Paths.
     */
    public static Path[] getPaths(FileStatus[] stats) {
      if (stats == null) {
        return null;
      }
      if (stats.length == 0) {
        return new Path[0];
      }
      Path[] res = new Path[stats.length];
      for (int i = 0; i < stats.length; i++) {
        res[i] = stats[i].getPath();
      }
      return res;
    }

}