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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.commons.logging.Log;
24  import org.apache.commons.logging.LogFactory;
25  import org.apache.hadoop.classification.InterfaceAudience;
26  import org.apache.hadoop.classification.InterfaceStability;
27  import org.apache.hadoop.fs.Path;
28  import org.apache.hadoop.hbase.HBaseConfiguration;
29  import org.apache.hadoop.hbase.client.HTable;
30  import org.apache.hadoop.hbase.util.Bytes;
31  import org.apache.hadoop.mapred.FileInputFormat;
32  import org.apache.hadoop.mapred.JobConf;
33  import org.apache.hadoop.mapred.JobConfigurable;
34  import org.apache.hadoop.util.StringUtils;
35  
36  /**
37   * Convert HBase tabular data into a format that is consumable by Map/Reduce.
38   */
39  @Deprecated
40  @InterfaceAudience.Public
41  @InterfaceStability.Stable
42  public class TableInputFormat extends TableInputFormatBase implements
43      JobConfigurable {
44    private static final Log LOG = LogFactory.getLog(TableInputFormat.class);
45  
46    /**
47     * space delimited list of columns
48     */
49    public static final String COLUMN_LIST = "hbase.mapred.tablecolumns";
50  
51    public void configure(JobConf job) {
52      Path[] tableNames = FileInputFormat.getInputPaths(job);
53      String colArg = job.get(COLUMN_LIST);
54      String[] colNames = colArg.split(" ");
55      byte [][] m_cols = new byte[colNames.length][];
56      for (int i = 0; i < m_cols.length; i++) {
57        m_cols[i] = Bytes.toBytes(colNames[i]);
58      }
59      setInputColumns(m_cols);
60      try {
61        setHTable(new HTable(HBaseConfiguration.create(job), tableNames[0].getName()));
62      } catch (Exception e) {
63        LOG.error(StringUtils.stringifyException(e));
64      }
65    }
66  
67    public void validateInput(JobConf job) throws IOException {
68      // expecting exactly one path
69      Path [] tableNames = FileInputFormat.getInputPaths(job);
70      if (tableNames == null || tableNames.length > 1) {
71        throw new IOException("expecting one table name");
72      }
73  
74      // connected to table?
75      if (getHTable() == null) {
76        throw new IOException("could not connect to table '" +
77          tableNames[0].getName() + "'");
78      }
79  
80      // expecting at least one column
81      String colArg = job.get(COLUMN_LIST);
82      if (colArg == null || colArg.length() == 0) {
83        throw new IOException("expecting at least one column");
84      }
85    }
86  }