HBase Filter 過濾器之 DependentColumnFilter 詳解-有解無憂

**前言：**本文詳細介紹了 HBase DependentColumnFilter 過濾器 Java&Shell API 的使用，并貼出了相關示例代碼以供參考，DependentColumnFilter 也稱參考列過濾器，是一種允許用戶指定一個參考列或參考列來過濾其他列的過濾器，過濾的原則是基于參考列的時間戳來進行篩選，

該過濾器嘗試找到該列所在的每一行，并回傳該行具有相同時間戳的全部鍵值對;如果某行不包含這個指定的列，則什么都不回傳，引數dropDependentColumn 決定參考列被回傳還是丟棄，為true時表示參考列被回傳，為false時表示被丟棄，可以把DependentColumnFilter理解為一個valueFilter和一個時間戳過濾器的組合，如果想要獲取同一時間線的資料可以考慮使用此過濾器，比較器細節及原理請參照之前的更文：HBase Filter 過濾器之比較器 Comparator 原理及原始碼學習，

一，Java Api

頭部代碼

public class DependentColumnFilterDemo {

    private static boolean isok = false;
    private static String tableName = "test";
    private static String[] cfs = new String[]{"f1", "f2"};
    private static String[] data1 = new String[]{"row-1:f2:c3:1234abc56", "row-3:f1:c3:1234321"};
    private static String[] data2 = new String[]{
            "row-1:f1:c1:abcdefg", "row-1:f2:c2:abc", "row-2:f1:c1:abc123456", "row-2:f2:c2:1234abc567"
    };

    public static void main(String[] args) throws IOException, InterruptedException {

        MyBase myBase = new MyBase();
        Connection connection = myBase.createConnection();
        if (isok) {
            myBase.deleteTable(connection, tableName);
            myBase.createTable(connection, tableName, cfs);
            // 造資料
            myBase.putRows(connection, tableName, data1);  // 第一批資料
            Thread.sleep(10);
            myBase.putRows(connection, tableName, data2);  // 第二批資料
        }
        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，

        // 構造方法一
        DependentColumnFilter filter = new DependentColumnFilter(Bytes.toBytes("f1"), Bytes.toBytes("c1"));  // [row-1:f1:c1:abcdefg, row-1:f2:c2:abc, row-2:f1:c1:abc123456, row-2:f2:c2:1234abc567]

        // 構造方法二 boolean dropDependentColumn=true
        DependentColumnFilter filter = new DependentColumnFilter(Bytes.toBytes("f1"), Bytes.toBytes("c1"), true);  // [row-1:f2:c2:abc, row-2:f2:c2:1234abc567]

        // 構造方法二 boolean dropDependentColumn=false  默認為false
        DependentColumnFilter filter = new DependentColumnFilter(Bytes.toBytes("f1"), Bytes.toBytes("c1"), false); // [row-1:f1:c1:abcdefg, row-1:f2:c2:abc, row-2:f1:c1:abc123456, row-2:f2:c2:1234abc567]

        // 構造方法三 + BinaryComparator 比較器過濾資料
        DependentColumnFilter filter = new DependentColumnFilter(Bytes.toBytes("f1"), Bytes.toBytes("c1"), false,
                CompareFilter.CompareOp.EQUAL, new BinaryComparator(Bytes.toBytes("abcdefg"))); // [row-1:f1:c1:abcdefg, row-1:f2:c2:abc]

        // 構造方法三 + BinaryPrefixComparator 比較器過濾資料
        DependentColumnFilter filter = new DependentColumnFilter(Bytes.toBytes("f1"), Bytes.toBytes("c1"), false,
                CompareFilter.CompareOp.EQUAL, new BinaryPrefixComparator(Bytes.toBytes("abc")));  // [row-1:f1:c1:abcdefg, row-1:f2:c2:abc, row-2:f1:c1:abc123456, row-2:f2:c2:1234abc567]

        // 構造方法三 + SubstringComparator 比較器過濾資料
        DependentColumnFilter filter = new DependentColumnFilter(Bytes.toBytes("f1"), Bytes.toBytes("c1"), false,
                CompareFilter.CompareOp.EQUAL, new SubstringComparator("1234"));  // [row-2:f1:c1:abc123456, row-2:f2:c2:1234abc567]

        // 構造方法三 + RegexStringComparator 比較器過濾資料
        DependentColumnFilter filter = new DependentColumnFilter(Bytes.toBytes("f1"), Bytes.toBytes("c1"), false,
                CompareFilter.CompareOp.EQUAL, new RegexStringComparator("[a-z]"));  // [row-1:f1:c1:abcdefg, row-1:f2:c2:abc, row-2:f1:c1:abc123456, row-2:f2:c2:1234abc567]

        // 構造方法三 + RegexStringComparator 比較器過濾資料
        DependentColumnFilter filter = new DependentColumnFilter(Bytes.toBytes("f1"), Bytes.toBytes("c1"), false,
                CompareFilter.CompareOp.EQUAL, new RegexStringComparator("1234[a-z]"));  // []  思考題：與上例對比，想想為什么為空？

該過濾器同時也支持各比較器的不同比較語法，同之前介紹的各種過濾器是一樣的，這里不再一一舉例了，

尾部代碼

		scan.setFilter(filter);
        ResultScanner scanner = table.getScanner(scan);
        Iterator<Result> iterator = scanner.iterator();
        LinkedList<String> keys = new LinkedList<>();
        while (iterator.hasNext()) {
            String key = "";
            Result result = iterator.next();
            for (Cell cell : result.rawCells()) {
                byte[] rowkey = CellUtil.cloneRow(cell);
                byte[] family = CellUtil.cloneFamily(cell);
                byte[] column = CellUtil.cloneQualifier(cell);
                byte[] value = https://www.cnblogs.com/zpb2016/p/CellUtil.cloneValue(cell);
                key = Bytes.toString(rowkey) + ":" + Bytes.toString(family) + ":" + Bytes.toString(column) + ":" + Bytes.toString(value);
                keys.add(key);
            }
        }
        System.out.println(keys);
        scanner.close();
        table.close();
        connection.close();
    }
}

二，Shell Api

HBase test 表資料一覽：

hbase(main):009:0> scan 'test'
ROW                                              COLUMN+CELL
 row-1                                           column=f1:c1, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abcdefg
 row-1                                           column=f2:c2, timestamp=1589794115268, value=abc
 row-1                                           column=f2:c3, timestamp=1589794115241, value=1234abc56
 row-2                                           column=f1:c1, timestamp=1589794115268, value=abc123456
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
 row-3                                           column=f1:c3, timestamp=1589794115241, value=1234321
3 row(s) in 0.0280 seconds

0. 簡單構造方法

hbase(main):006:0> scan 'test',{FILTER=>"DependentColumnFilter('f1','c1')"}
ROW                                              COLUMN+CELL
 row-1                                           column=f1:c1, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abcdefg
 row-1                                           column=f2:c2, timestamp=1589794115268, value=abc
 row-2                                           column=f1:c1, timestamp=1589794115268, value=abc123456
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0450 seconds

hbase(main):008:0> scan'test',{FILTER=>"DependentColumnFilter('f1','c1',false)"}
ROW                                              COLUMN+CELL
 row-1                                           column=f1:c1, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abcdefg
 row-1                                           column=f2:c2, timestamp=1589794115268, value=abc
 row-2                                           column=f1:c1, timestamp=1589794115268, value=abc123456
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0310 seconds

hbase(main):007:0> scan'test',{FILTER=>"DependentColumnFilter('f1','c1',true)"}
ROW                                              COLUMN+CELL
 row-1                                           column=f2:c2, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abc
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0250 seconds

1. BinaryComparator 構造過濾器

方式一：

hbase(main):004:0> scan 'test',{FILTER=>"DependentColumnFilter('f1','c1',false,=,'binary:abcdefg')"}
ROW                                              COLUMN+CELL
 row-1                                           column=f1:c1, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abcdefg
 row-1                                           column=f2:c2, timestamp=1589794115268, value=abc
1 row(s) in 0.0330 seconds

hbase(main):005:0> scan'test',{FILTER=>"DependentColumnFilter('f1','c1',true,=,'binary:abcdefg')"}
ROW                                              COLUMN+CELL
 row-1                                           column=f2:c2, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abc
1 row(s) in 0.0120 seconds

支持的比較運算子：= != > >= < <=，不再一一舉例，

方式二：

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

hbase(main):016:0> scan 'test',{FILTER => DependentColumnFilter.new(Bytes.toBytes("f1"), Bytes.toBytes("c1"), false,CompareFilter::CompareOp.valueOf('EQUAL'), BinaryComparator.new(Bytes.toBytes('abcdefg')))}
ROW                                              COLUMN+CELL
 row-1                                           column=f1:c1, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abcdefg
 row-1                                           column=f2:c2, timestamp=1589794115268, value=abc
1 row(s) in 0.0170 seconds

hbase(main):017:0> scan'test',{FILTER => DependentColumnFilter.new(Bytes.toBytes("f1"), Bytes.toBytes("c1"), true,CompareFilter::CompareOp.valueOf('EQUAL'), BinaryComparator.new(Bytes.toBytes('abcdefg')))}
ROW                                              COLUMN+CELL
 row-1                                           column=f2:c2, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abc
1 row(s) in 0.0140 seconds

支持的比較運算子：LESS、LESS_OR_EQUAL、EQUAL、NOT_EQUAL、GREATER、GREATER_OR_EQUAL，不再一一舉例，

推薦使用方式一，更簡潔方便，

2. BinaryPrefixComparator 構造過濾器

方式一：

hbase(main):019:0> scan 'test',{FILTER=>"DependentColumnFilter('f1','c1',false,=,'binaryprefix:abc')"}
ROW                                              COLUMN+CELL
 row-1                                           column=f1:c1, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abcdefg
 row-1                                           column=f2:c2, timestamp=1589794115268, value=abc
 row-2                                           column=f1:c1, timestamp=1589794115268, value=abc123456
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0330 seconds

hbase(main):020:0> scan'test',{FILTER=>"DependentColumnFilter('f1','c1',true,=,'binaryprefix:abc')"}
ROW                                              COLUMN+CELL
 row-1                                           column=f2:c2, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abc
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0600 seconds

方式二：

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

hbase(main):023:0> scan 'test',{FILTER => DependentColumnFilter.new(Bytes.toBytes("f1"), Bytes.toBytes("c1"), false,CompareFilter::CompareOp.valueOf('EQUAL'), BinaryPrefixComparator.new(Bytes.toBytes('abc')))}
ROW                                              COLUMN+CELL
 row-1                                           column=f1:c1, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abcdefg
 row-1                                           column=f2:c2, timestamp=1589794115268, value=abc
 row-2                                           column=f1:c1, timestamp=1589794115268, value=abc123456
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0180 seconds

hbase(main):022:0> scan'test',{FILTER => DependentColumnFilter.new(Bytes.toBytes("f1"), Bytes.toBytes("c1"), true,CompareFilter::CompareOp.valueOf('EQUAL'), BinaryPrefixComparator.new(Bytes.toBytes('abc')))}
ROW                                              COLUMN+CELL
 row-1                                           column=f2:c2, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abc
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0190 seconds

其它同上，

3. SubstringComparator 構造過濾器

方式一：

hbase(main):025:0> scan 'test',{FILTER=>"DependentColumnFilter('f1','c1',false,=,'substring:abc')"}
ROW                                              COLUMN+CELL
 row-1                                           column=f1:c1, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abcdefg
 row-1                                           column=f2:c2, timestamp=1589794115268, value=abc
 row-2                                           column=f1:c1, timestamp=1589794115268, value=abc123456
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0340 seconds

hbase(main):024:0> scan'test',{FILTER=>"DependentColumnFilter('f1','c1',true,=,'substring:abc')"}
ROW                                              COLUMN+CELL
 row-1                                           column=f2:c2, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abc
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0160 seconds

方式二：

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

hbase(main):028:0> scan 'test',{FILTER => DependentColumnFilter.new(Bytes.toBytes("f1"), Bytes.toBytes("c1"), false,CompareFilter::CompareOp.valueOf('EQUAL'), SubstringComparator.new('abc'))}
ROW                                              COLUMN+CELL
 row-1                                           column=f1:c1, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abcdefg
 row-1                                           column=f2:c2, timestamp=1589794115268, value=abc
 row-2                                           column=f1:c1, timestamp=1589794115268, value=abc123456
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0150 seconds

hbase(main):029:0> scan'test',{FILTER => DependentColumnFilter.new(Bytes.toBytes("f1"), Bytes.toBytes("c1"), true,CompareFilter::CompareOp.valueOf('EQUAL'), SubstringComparator.new('abc'))}
ROW                                              COLUMN+CELL
 row-1                                           column=f2:c2, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abc
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0170 seconds

區別于上的是這里直接傳入字串進行比較，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.DependentColumnFilter

hbase(main):035:0> scan 'test',{FILTER => DependentColumnFilter.new(Bytes.toBytes("f1"), Bytes.toBytes("c1"), false,CompareFilter::CompareOp.valueOf('EQUAL'), RegexStringComparator.new('[a-z]'))}
ROW                                              COLUMN+CELL
 row-1                                           column=f1:c1, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abcdefg
 row-1                                           column=f2:c2, timestamp=1589794115268, value=abc
 row-2                                           column=f1:c1, timestamp=1589794115268, value=abc123456
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0170 seconds

hbase(main):034:0* scan'test',{FILTER => DependentColumnFilter.new(Bytes.toBytes("f1"), Bytes.toBytes("c1"), true,CompareFilter::CompareOp.valueOf('EQUAL'), RegexStringComparator.new('[a-z]'))}
ROW                                              COLUMN+CELL
 row-1                                           column=f2:c2, timestamp=1589794115268, value=https://www.cnblogs.com/zpb2016/p/abc
 row-2                                           column=f2:c2, timestamp=1589794115268, value=1234abc567
2 row(s) in 0.0150 seconds

該比較器直接傳入字串進行比較，且只支持EQUAL和NOT_EQUAL兩種比較符，若想使用第一種方式可以傳入regexstring試一下，我的版本有點低暫時不支持，不再演示了，

注意這里的正則匹配指包含關系，對應底層find()方法，

DependentColumnFilter不支持使用LongComparator比較器，且BitComparator、NullComparator比較器用之甚少，也不再介紹，

到此為止，所有的比較過濾器就總結完畢了，

查看文章全部源代碼請訪以下GitHub地址：

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

掃描二維碼關注博主公眾號

轉載請注明出處！歡迎關注本人微信公眾號【HBase作業筆記】

轉載請註明出處，本文鏈接：https://www.uj5u.com/shujuku/6020.html

標籤：大數據

上一篇：2020年數學建模國賽B題題目和解題思路

下一篇：北斗對時設備（GPS校時產品）在數字城市系統中的應用