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1   /*
2    * Copyright 2010 The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  package org.apache.hadoop.hbase.client.coprocessor;
21  
22  import org.apache.hadoop.hbase.io.HbaseObjectWritable;
23  import org.apache.hadoop.hbase.util.Bytes;
24  import org.apache.hadoop.hbase.util.Classes;
25  import org.apache.hadoop.io.Writable;
26  
27  import java.io.DataInput;
28  import java.io.DataOutput;
29  import java.io.IOException;
30  import java.io.Serializable;
31  
32  /**
33   * Represents the return value from a
34   * {@link org.apache.hadoop.hbase.client.coprocessor.Exec} invocation.
35   * This simply wraps the value for easier
36   * {@link org.apache.hadoop.hbase.io.HbaseObjectWritable}
37   * serialization.
38   *
39   * <p>
40   * This class is used internally by the HBase client code to properly serialize
41   * responses from {@link org.apache.hadoop.hbase.ipc.CoprocessorProtocol}
42   * method invocations.  It should not be used directly by clients.
43   * </p>
44   *
45   * @see Exec
46   * @see org.apache.hadoop.hbase.client.HTable#coprocessorExec(Class, byte[], byte[], org.apache.hadoop.hbase.client.coprocessor.Batch.Call)
47   * @see org.apache.hadoop.hbase.client.HTable#coprocessorExec(Class, byte[], byte[], org.apache.hadoop.hbase.client.coprocessor.Batch.Call, org.apache.hadoop.hbase.client.coprocessor.Batch.Callback)
48   */
49  public class ExecResult implements Writable {
50    private byte[] regionName;
51    private Object value;
52  
53    public ExecResult() {
54    }
55  
56    public ExecResult(byte[] region, Object value) {
57      this.regionName = region;
58      this.value = value;
59    }
60  
61    public byte[] getRegionName() {
62      return regionName;
63    }
64  
65    public Object getValue() {
66      return value;
67    }
68  
69    @Override
70    public void write(DataOutput out) throws IOException {
71      Bytes.writeByteArray(out, regionName);
72      HbaseObjectWritable.writeObject(out, value,
73          value != null ? value.getClass() : Writable.class, null);
74    }
75  
76    @Override
77    public void readFields(DataInput in) throws IOException {
78      regionName = Bytes.readByteArray(in);
79      value = HbaseObjectWritable.readObject(in, null);
80    }
81  }