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
21 package org.apache.hadoop.hbase.filter;
22
23 import org.apache.hadoop.hbase.KeyValue;
24 import org.apache.hadoop.hbase.client.Get;
25
26 /**
27 * This filter is used to filter based on the column qualifier. It takes an
28 * operator (equal, greater, not equal, etc) and a byte [] comparator for the
29 * column qualifier portion of a key.
30 * <p>
31 * This filter can be wrapped with {@link WhileMatchFilter} and {@link SkipFilter}
32 * to add more control.
33 * <p>
34 * Multiple filters can be combined using {@link FilterList}.
35 * <p>
36 * If an already known column qualifier is looked for, use {@link Get#addColumn}
37 * directly rather than a filter.
38 */
39 public class QualifierFilter extends CompareFilter {
40
41 /**
42 * Writable constructor, do not use.
43 */
44 public QualifierFilter() {
45 }
46
47 /**
48 * Constructor.
49 * @param qualifierCompareOp the compare op for column qualifier matching
50 * @param qualifierComparator the comparator for column qualifier matching
51 */
52 public QualifierFilter(final CompareOp qualifierCompareOp,
53 final WritableByteArrayComparable qualifierComparator) {
54 super(qualifierCompareOp, qualifierComparator);
55 }
56
57 @Override
58 public ReturnCode filterKeyValue(KeyValue v) {
59 int qualifierLength = v.getQualifierLength();
60 if (qualifierLength > 0) {
61 if (doCompare(this.compareOp, this.comparator, v.getBuffer(),
62 v.getQualifierOffset(), qualifierLength)) {
63 return ReturnCode.SKIP;
64 }
65 }
66 return ReturnCode.INCLUDE;
67 }
68 }