sequencefileinputformat.java

hadoop:Nutch集群平台

/**
 * Copyright 2005 The Apache Software Foundation
 *
 * Licensed 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.hadoop.mapred;

import java.io.IOException;

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

import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.MapFile;

/** An {@link InputFormat} for {@link SequenceFile}s. */
public class SequenceFileInputFormat extends InputFormatBase {

  public SequenceFileInputFormat() {
    setMinSplitSize(SequenceFile.SYNC_INTERVAL);
  }

  protected Path[] listPaths(FileSystem fs, JobConf job)
    throws IOException {

    Path[] files = super.listPaths(fs, job);
    for (int i = 0; i < files.length; i++) {
      Path file = files[i];
      if (fs.isDirectory(file)) {                 // it's a MapFile
        files[i] = new Path(file, MapFile.DATA_FILE_NAME); // use the data file
      }
    }
    return files;
  }

  public RecordReader getRecordReader(FileSystem fs, FileSplit split,
                                      JobConf job, Reporter reporter)
    throws IOException {

    reporter.setStatus(split.toString());

    return new SequenceFileRecordReader(job, split);
  }

}