欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  IT编程

HBase Filter 过滤器之RowFilter详解

程序员文章站 2022-06-24 22:47:03
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: "HBase Filter ......

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:hbase filter 过滤器之比较器 comparator 原理及源码学习

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

HBase Filter 过滤器之RowFilter详解

转载请注明出处!欢迎关注本人微信公众号【hbase工作笔记】