HBaseFilter过滤器之QualifierFilter详解

database

前言:本文详细介绍了 HBase QualifierFilter 过滤器 Java&Shell API 的使用,并贴出了相关示例代码以供参考。QualifierFilter 基于列名进行过滤,在工作中涉及到需要通过HBase 列名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

/**

* 用于列名(Qualifier)过滤。

*/

public class QualifierFilterDemo {

private static boolean isok = false;

private static String tableName = "test";

private static String[] cfs = new String[]{"f"};

private static String[] data = new String[]{

"row-1:f:name:Wang", "row-1:f:age:20",

"row-2:f:name:Zhou", "row-2:f:age:10",

"row-3:f:gender:男", "row-3:f:name:Li",

"row-4:f:namana:xyz", "row-4:f:age:Zhao"

};

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);

// 造数据

myBase.putRows(connection, tableName, data);

}

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

        QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.EQUAL, new BinaryComparator(Bytes.toBytes("age"))); // [row-1:f:age, row-2:f:age, row-4:f:age]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.NOT_EQUAL, new BinaryComparator(Bytes.toBytes("name"))); // [row-1:f:age, row-2:f:age, row-3:f:gender, row-4:f:age, row-4:f:namana]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.GREATER, new BinaryComparator(Bytes.toBytes("gender"))); // [row-1:f:name, row-2:f:name, row-3:f:name, row-4:f:namana]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.GREATER_OR_EQUAL, new BinaryComparator(Bytes.toBytes("name"))); // [row-1:f:name, row-2:f:name, row-3:f:name]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.LESS, new BinaryComparator(Bytes.toBytes("gender"))); // [row-1:f:age, row-2:f:age, row-4:f:age]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.LESS_OR_EQUAL, new BinaryComparator(Bytes.toBytes("gender"))); // [row-1:f:age, row-2:f:age, row-3:f:gender, row-4:f:age]

2. BinaryPrefixComparator 构造过滤器

        QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.EQUAL, new BinaryPrefixComparator(Bytes.toBytes("nam"))); // [row-1:f:name, row-2:f:name, row-3:f:name, row-4:f:namana]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.NOT_EQUAL, new BinaryPrefixComparator(Bytes.toBytes("nam"))); // [row-1:f:age, row-2:f:age, row-3:f:gender, row-4:f:age]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.GREATER, new BinaryPrefixComparator(Bytes.toBytes("g"))); // [row-1:f:name, row-2:f:name, row-3:f:name, row-4:f:namana]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.GREATER_OR_EQUAL, new BinaryPrefixComparator(Bytes.toBytes("n"))); // [row-1:f:name, row-2:f:name, row-3:f:name, row-4:f:namana]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.LESS, new BinaryPrefixComparator(Bytes.toBytes("m"))); // [row-1:f:age, row-2:f:age, row-3:f:gender, row-4:f:age]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.LESS_OR_EQUAL, new BinaryPrefixComparator(Bytes.toBytes("a"))); // [row-1:f:age, row-2:f:age, row-4:f:age]

3. SubstringComparator 构造过滤器

        QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.EQUAL, new SubstringComparator("g")); // [row-1:f:age, row-2:f:age, row-3:f:gender, row-4:f:age]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.NOT_EQUAL, new SubstringComparator("n")); // [row-1:f:age, row-2:f:age, row-4:f:age]

4. RegexStringComparator 构造过滤器

        QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.NOT_EQUAL, new RegexStringComparator("nam")); // [row-1:f:age, row-2:f:age, row-3:f:gender, row-4:f:age]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.EQUAL, new RegexStringComparator("nam")); // [row-1:f:name, row-2:f:name, row-3:f:name, row-4:f:namana]

QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.EQUAL, new RegexStringComparator("n[a-z]m")); // [row-1:f:name, row-2:f:name, row-3:f:name, row-4:f:namana]

尾部代码

        scan.setFilter(qualifierFilter);

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):003:0> scan "test",{FILTER=>"QualifierFilter(=,"binary:age")"}

ROW COLUMN+CELL

row-1 column=f:age, timestamp=1589252853542, value=20

row-2 column=f:age, timestamp=1589252853542, value=10

row-4 column=f:age, timestamp=1589252853542, value=Zhao

3 row(s) in 0.0680 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.QualifierFilter

hbase(main):010:0> scan "test",{FILTER => QualifierFilter.new(CompareFilter::CompareOp.valueOf("EQUAL"), BinaryComparator.new(Bytes.toBytes("age")))}

ROW COLUMN+CELL

row-1 column=f:age, timestamp=1589252853542, value=20

row-2 column=f:age, timestamp=1589252853542, value=10

row-4 column=f:age, timestamp=1589252853542, value=Zhao

3 row(s) in 0.0400 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):011:0> scan "test",{FILTER=>"QualifierFilter(=,"binaryprefix:nam")"}

ROW COLUMN+CELL

row-1 column=f:name, timestamp=1589252853542, value=Wang

row-2 column=f:name, timestamp=1589252853542, value=Zhou

row-3 column=f:name, timestamp=1589252853542, value=Li

row-4 column=f:namana, timestamp=1589252853542, value=xyz

4 row(s) in 0.0410 seconds

方式二:

import org.apache.hadoop.hbase.filter.CompareFilter

import org.apache.hadoop.hbase.filter.BinaryPrefixComparator

import org.apache.hadoop.hbase.filter.QualifierFilter

hbase(main):014:0> scan "test",{FILTER => QualifierFilter.new(CompareFilter::CompareOp.valueOf("EQUAL"), BinaryPrefixComparator.new(Bytes.toBytes("nam")))}

ROW COLUMN+CELL

row-1 column=f:name, timestamp=1589252853542, value=Wang

row-2 column=f:name, timestamp=1589252853542, value=Zhou

row-3 column=f:name, timestamp=1589252853542, value=Li

row-4 column=f:namana, timestamp=1589252853542, value=xyz

4 row(s) in 0.0200 seconds

其它同上。

3. SubstringComparator 构造过滤器

方式一:

hbase(main):015:0> scan "test",{FILTER=>"QualifierFilter(=,"substring:am")"}

ROW COLUMN+CELL

row-1 column=f:name, timestamp=1589252853542, value=Wang

row-2 column=f:name, timestamp=1589252853542, value=Zhou

row-3 column=f:name, timestamp=1589252853542, value=Li

row-4 column=f:namana, timestamp=1589252853542, value=xyz

4 row(s) in 0.0230 seconds

方式二:

import org.apache.hadoop.hbase.filter.CompareFilter

import org.apache.hadoop.hbase.filter.SubstringComparator

import org.apache.hadoop.hbase.filter.QualifierFilter

hbase(main):017:0> scan "test",{FILTER => QualifierFilter.new(CompareFilter::CompareOp.valueOf("EQUAL"), SubstringComparator.new("am"))}

ROW COLUMN+CELL

row-1 column=f:name, timestamp=1589252853542, value=Wang

row-2 column=f:name, timestamp=1589252853542, value=Zhou

row-3 column=f:name, timestamp=1589252853542, value=Li

row-4 column=f:namana, timestamp=1589252853542, value=xyz

4 row(s) in 0.0220 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.QualifierFilter

hbase(main):019:0> scan "test",{FILTER => QualifierFilter.new(CompareFilter::CompareOp.valueOf("EQUAL"), RegexStringComparator.new("n[a-z]m"))}

ROW COLUMN+CELL

row-1 column=f:name, timestamp=1589252853542, value=Wang

row-2 column=f:name, timestamp=1589252853542, value=Zhou

row-3 column=f:name, timestamp=1589252853542, value=Li

row-4 column=f:namana, timestamp=1589252853542, value=xyz

4 row(s) in 0.0250 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。

QualifierFilter 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/QualifierFilterDemo.java

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