hbase行键过滤器RowFilter

转至http://blog.chinaunix.net/uid-77311-id-4617954.html 

hbase行键过滤器RowFilter 2014-11-13 09:57:00

分类： HADOOP

RowFilter是用来对rowkey进行过滤的,比较符如下:

Operator

Description

LESS

小于

LESS_OR_EQUAL

小于等于

EQUAL

等于

NOT_EQUAL

不等于

GREATER_OR_EQUAL

大于等于

GREATER

大于

NO_OP

排除所有

Comparator

Description

Bytes.compareTo()比较BinaryPrefixComparator

和

Does not compare against an actual value but whether a given one is null, or not null.

Performs a bitwise comparison, providing a BitwiseOp class with AND, OR, and XOR operators.

contains()来判断<span "="" style="word-wrap: break-word; font-size: 9pt;">

下面是相关比较符的例子

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1. package com.hxl;
   
2. 
   
3. import java.io.IOException;
   
4. import org.apache.hadoop.conf.Configuration;
   
5. import org.apache.hadoop.hbase.Cell;
   
6. import org.apache.hadoop.hbase.CellUtil;
   
7. import org.apache.hadoop.hbase.KeyValue;
   
8. import org.apache.hadoop.hbase.client.HTable;
   
9. import org.apache.hadoop.hbase.client.Result;
   
10. import org.apache.hadoop.hbase.client.ResultScanner;
    
11. import org.apache.hadoop.hbase.client.Scan;
    
12. import org.apache.hadoop.hbase.filter.BinaryComparator;
    
13. import org.apache.hadoop.hbase.filter.CompareFilter;
    
14. import org.apache.hadoop.hbase.filter.Filter;
    
15. import org.apache.hadoop.hbase.filter.RowFilter;
    
16. import org.apache.hadoop.hbase.util.Bytes;
    
17. 
    
18. import com.hxl.ConnectDB;
    
19. 
    
20. public class RowFilterTest {
    
21. 
    
22.     public void rowfilter(String tablename, String rowkeyvalue) {
    
23.         Configuration configuration = null;
    
24.         configuration = new ConnectDB().getConf();
    
25. 
    
26.         try {
    
27.             HTable table = new HTable(configuration, tablename);
    
28. 
    
29.             Filter filter1 = new RowFilter(CompareFilter.CompareOp.EQUAL,
    
30.                     new BinaryComparator(Bytes.toBytes(rowkeyvalue)));
    
31.             // EQUAL =
    
32. 
    
33.             Scan s = new Scan();
    
34.             s.setFilter(filter1);
    
35.             ResultScanner rs = table.getScanner(s);
    
36. 
    
37.             for (Result r : rs) {
    
38.                 System.out.println("rowkey:" + new String(r.getRow()));
    
39.                 for (KeyValue keyValue : r.raw()) {
    
40.                     System.out.println("列族:" + new String(keyValue.getFamily())
    
41.                             + " 列:" + new String(keyValue.getQualifier()) + ":"
    
42.                             + new String(keyValue.getValue()));
    
43.                 }
    
44.             }
    
45. 
    
46.         } catch (IOException e) {
    
47.             // TODO Auto-generated catch block
    
48.             e.printStackTrace();
    
49. 
    
50.         }
    
51. 
    
52.     }
    
53. 
    
54. }

相关的过滤方法使用:
提取rowkey以01结尾数据
Filter filter = new RowFilter(CompareFilter.CompareOp.EQUAL,new RegexStringComparator(".*01$"));

提取rowkey以包含201407的数据
Filter filter = new RowFilter(CompareFilter.CompareOp.EQUAL,new SubstringComparator("201407"));


提取rowkey以123开头的数据
Filter filter = new RowFilter(CompareFilter.CompareOp.EQUAL,new BinaryPrefixComparator("123".getBytes()));


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