HBase Filter 過濾器之RowFilter詳解

前言：本文詳細介紹了HBase RowFilter過濾器Java&Shell API的使用，並貼出了相關示例代碼以供參考。RowFilter 基於行鍵進行過濾，在工做中涉及到須要經過HBase Rowkey進行數據過濾時能夠考慮使用它。比較器細節及原理請參照以前的更文：HBase Filter 過濾器之比較器 Comparator 原理及源碼學習

一。Java Api

頭部代碼

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); // 造數據
        }
        Table table = connection.getTable(TableName.valueOf(tableName));
        Scan scan = new Scan();

中部代碼
向右滑動滾動條可查看輸出結果。

1. BinaryComparator 構造過濾器

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 構造過濾器

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 構造過濾器

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 構造過濾器

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 構造過濾器

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]

尾部代碼

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 構造過濾器

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

支持的比較運算符：= != > >= < <=，再也不一一舉例。

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

支持的比較運算符：LESS、LESS_OR_EQUAL、EQUAL、NOT_EQUAL、GREATER、GREATER_OR_EQUAL，再也不一一舉例。

推薦使用方式一，更簡潔方便。

2. BinaryPrefixComparator 構造過濾器

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 構造過濾器

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

區別於上的是這裏直接傳入字符串進行比較，且只支持EQUAL和NOT_EQUAL兩種比較符。

4. RegexStringComparator 構造過濾器

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

該比較器直接傳入字符串進行比較，且只支持EQUAL和NOT_EQUAL兩種比較符。若想使用第一種方式能夠傳入regexstring試一下，個人版本有點低暫時不支持，再也不演示了。

注意這裏的正則匹配指包含關係，對應底層find()方法。

此外，RowFilter 不支持使用LongComparator比較器，且BitComparator、NullComparator 比較器用之甚少，也再也不介紹。

查看文章所有源代碼請訪如下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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