HBase Filter 过滤器之RowFilter详解

小莫騒麦歌曲,山东招生考试信息网,12593和17951的区别

前言：本文详细介绍了hbase rowfilter过滤器java&shell api的使用，并贴出了相关示例代码以供参考。rowfilter 基于行键进行过滤，在工作中涉及到需要通过hbase rowkey进行数据过滤时可以考虑使用它。比较器细节及原理请参照之前的更文：

一。java api

头部代码

public class rowfilterdemo {

    private static boolean isok = false;
    private static string tablename = "test";
    private static string[] cfs = new string[]{"f"};
    private static string[] data = new string[]{"row-ac:f:c1:v1", "row-ab:f:c2:v2", "row-bc:f:c3:v3", "row-abc:f:c4:v4"};

    public static void main(string[] args) throws ioexception {

        mybase mybase = new mybase();
        connection connection = mybase.createconnection();
        if (isok) {
            mybase.deletetable(connection, tablename);
            mybase.createtable(connection, tablename, cfs);
            mybase.putrows(connection, tablename, data); // 造数据
        }
        table table = connection.gettable(tablename.valueof(tablename));
        scan scan = new scan();

中部代码
向右滑动滚动条可查看输出结果。

1. binarycomparator 构造过滤器

        rowfilter rowfilter = new rowfilter(comparefilter.compareop.equal, new binarycomparator(bytes.tobytes("row-ac"))); // [row-ac]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.not_equal, new binarycomparator(bytes.tobytes("row-ac"))); // [row-ab, row-abc, row-bc]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.greater, new binarycomparator(bytes.tobytes("row-ac"))); // [row-bc]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.greater_or_equal, new binarycomparator(bytes.tobytes("row-ac"))); // [row-ac, row-bc]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.less, new binarycomparator(bytes.tobytes("row-ac"))); // [row-ab, row-abc]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.less_or_equal, new binarycomparator(bytes.tobytes("row-ac"))); // [row-ab, row-abc, row-ac]

2. binaryprefixcomparator 构造过滤器

        rowfilter rowfilter = new rowfilter(comparefilter.compareop.equal, new binaryprefixcomparator(bytes.tobytes("row-a"))); // [row-ab, row-abc, row-ac]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.not_equal, new binaryprefixcomparator(bytes.tobytes("row-a"))); // [row-bc]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.greater, new binaryprefixcomparator(bytes.tobytes("row-a"))); // [row-bc]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.greater_or_equal, new binaryprefixcomparator(bytes.tobytes("row-a"))); // [row-ab, row-abc, row-ac, row-bc]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.less, new binaryprefixcomparator(bytes.tobytes("row-a"))); // []
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.less_or_equal, new binaryprefixcomparator(bytes.tobytes("row-a"))); // [row-ab, row-abc, row-ac]

3. substringcomparator 构造过滤器

        rowfilter rowfilter = new rowfilter(comparefilter.compareop.equal, new substringcomparator("ab")); // [row-ab, row-abc]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.not_equal, new substringcomparator("ab")); // [row-ac, row-bc]

4. regexstringcomparator 构造过滤器

        rowfilter rowfilter = new rowfilter(comparefilter.compareop.not_equal, new regexstringcomparator("abc")); // [row-ab, row-ac, row-bc]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.equal, new regexstringcomparator("abc")); // [row-abc]
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.equal, new regexstringcomparator("a")); // [row-ab, row-abc, row-ac]

5. nullcomparator 构造过滤器

        rowfilter rowfilter = new rowfilter(comparefilter.compareop.equal, new nullcomparator()); // []
        rowfilter rowfilter = new rowfilter(comparefilter.compareop.not_equal, new nullcomparator()); // [row-ab, row-abc, row-ac, row-bc]

尾部代码

        scan.setfilter(rowfilter);
        resultscanner scanner = table.getscanner(scan);
        iterator<result> iterator = scanner.iterator();
        linkedlist<string> rowkeys = new linkedlist<>();
        while (iterator.hasnext()) {
            result result = iterator.next();
            string rowkey = bytes.tostring(result.getrow());
            rowkeys.add(rowkey);
        }
        system.out.println(rowkeys);
        scanner.close();
        table.close();
        connection.close();
    }
}

二。shell api

1. binarycomparator 构造过滤器

方式一：

hbase(main):006:0> scan 'test',{filter=>"rowfilter(=,'binary:row-ab')"}
row                                              column+cell                                                                                                                                   
 row-ab                                          column=f:c2, timestamp=1588156704669, value=v2                                                                                                
1 row(s) in 0.0140 seconds

支持的比较运算符：= != > >= < <=，不再一一举例。

方式二：

import org.apache.hadoop.hbase.filter.comparefilter
import org.apache.hadoop.hbase.filter.binarycomparator
import org.apache.hadoop.hbase.filter.rowfilter

hbase(main):016:0> scan 'test',{filter => rowfilter.new(comparefilter::compareop.valueof('equal'), binarycomparator.new(bytes.tobytes('row-ab')))}
row                                              column+cell                                                                                                                                   
 row-ab                                          column=f:c2, timestamp=1588156704669, value=v2                                                                                                
1 row(s) in 0.0310 seconds

支持的比较运算符：less、less_or_equal、equal、not_equal、greater、greater_or_equal，不再一一举例。

推荐使用方式一，更简洁方便。

2. binaryprefixcomparator 构造过滤器

方式一：

hbase(main):023:0> scan 'test',{filter=>"rowfilter(=,'binaryprefix:row-ab')"}
row                                              column+cell                                                                                                                                   
 row-ab                                          column=f:c2, timestamp=1588156704669, value=v2                                                                                                
 row-abc                                         column=f:c4, timestamp=1588156704669, value=v4                                                                                                
2 row(s) in 0.0360 seconds

方式二：

import org.apache.hadoop.hbase.filter.comparefilter
import org.apache.hadoop.hbase.filter.binaryprefixcomparator
import org.apache.hadoop.hbase.filter.rowfilter

hbase(main):027:0> scan 'test',{filter => rowfilter.new(comparefilter::compareop.valueof('equal'), binaryprefixcomparator.new(bytes.tobytes('row-ab')))}
row                                              column+cell                                                                                                                                   
 row-ab                                          column=f:c2, timestamp=1588156704669, value=v2                                                                                                
 row-abc                                         column=f:c4, timestamp=1588156704669, value=v4                                                                                                
2 row(s) in 0.0110 seconds

其它同上。

3. substringcomparator 构造过滤器

方式一：

hbase(main):001:0> scan 'test',{filter=>"rowfilter(=,'substring:row-ab')"}
row                                              column+cell                                                                                                                                   
 row-ab                                          column=f:c2, timestamp=1588156704669, value=v2                                                                                                
 row-abc                                         column=f:c4, timestamp=1588156704669, value=v4                                                                                                
2 row(s) in 0.3200 seconds

方式二：

import org.apache.hadoop.hbase.filter.comparefilter
import org.apache.hadoop.hbase.filter.substringcomparator
import org.apache.hadoop.hbase.filter.rowfilter

hbase(main):007:0> scan 'test',{filter => rowfilter.new(comparefilter::compareop.valueof('equal'), substringcomparator.new('row-ab'))}
row                                              column+cell                                                                                                                                   
 row-ab                                          column=f:c2, timestamp=1588156704669, value=v2                                                                                                
 row-abc                                         column=f:c4, timestamp=1588156704669, value=v4                                                                                                
2 row(s) in 0.0230 seconds

区别于上的是这里直接传入字符串进行比较，且只支持equal和not_equal两种比较符。

4. regexstringcomparator 构造过滤器

import org.apache.hadoop.hbase.filter.comparefilter
import org.apache.hadoop.hbase.filter.regexstringcomparator
import org.apache.hadoop.hbase.filter.rowfilter

hbase(main):007:0> scan 'test',{filter => rowfilter.new(comparefilter::compareop.valueof('equal'), regexstringcomparator.new('row-ab'))}
row                                              column+cell                                                                                                                                   
 row-ab                                          column=f:c2, timestamp=1588156704669, value=v2                                                                                                
 row-abc                                         column=f:c4, timestamp=1588156704669, value=v4                                                                                                
2 row(s) in 0.0230 seconds

该比较器直接传入字符串进行比较，且只支持equal和not_equal两种比较符。若想使用第一种方式可以传入regexstring试一下，我的版本有点低暂时不支持，不再演示了。

注意这里的正则匹配指包含关系，对应底层find()方法。

此外，rowfilter 不支持使用longcomparator比较器，且bitcomparator、nullcomparator 比较器用之甚少，也不再介绍。

查看文章全部源代码请访以下github地址：

https://github.com/zhoupengbo/demos-bigdata/blob/master/hbase/hbase-filters-demos/src/main/java/com/zpb/demos/rowfilterdemo.java

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