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1   /**
2    *
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *     http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing, software
14   * distributed under the License is distributed on an "AS IS" BASIS,
15   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16   * See the License for the specific language governing permissions and
17   * limitations under the License.
18   */
19  package org.apache.hadoop.hbase.mapred;
20  
21  import java.io.IOException;
22  
23  import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
24  import org.apache.hadoop.hbase.client.Result;
25  import org.apache.hadoop.mapred.JobConf;
26  import org.apache.hadoop.mapred.MapReduceBase;
27  import org.apache.hadoop.mapred.OutputCollector;
28  import org.apache.hadoop.mapred.Reporter;
29  
30  /**
31   * Pass the given key and record as-is to reduce
32   */
33  @Deprecated
34  public class IdentityTableMap
35  extends MapReduceBase
36  implements TableMap<ImmutableBytesWritable, Result> {
37  
38    /** constructor */
39    public IdentityTableMap() {
40      super();
41    }
42  
43    /**
44     * Use this before submitting a TableMap job. It will
45     * appropriately set up the JobConf.
46     *
47     * @param table table name
48     * @param columns columns to scan
49     * @param mapper mapper class
50     * @param job job configuration
51     */
52    @SuppressWarnings("unchecked")
53    public static void initJob(String table, String columns,
54      Class<? extends TableMap> mapper, JobConf job) {
55      TableMapReduceUtil.initTableMapJob(table, columns, mapper,
56        ImmutableBytesWritable.class,
57        Result.class, job);
58    }
59  
60    /**
61     * Pass the key, value to reduce
62     * @param key
63     * @param value
64     * @param output
65     * @param reporter
66     * @throws IOException
67     */
68    public void map(ImmutableBytesWritable key, Result value,
69        OutputCollector<ImmutableBytesWritable,Result> output,
70        Reporter reporter) throws IOException {
71  
72      // convert
73      output.collect(key, value);
74    }
75  }