hbase行键过滤器RowFilter

原创
2018/08/07 16:10
阅读数 1.8K

RowFilter是用来对rowkey进行过滤的,比较符如下:
 

Operator

Description

LESS

小于

LESS_OR_EQUAL

小于等于

EQUAL

等于

NOT_EQUAL

不等于

GREATER_OR_EQUAL

大于等于

GREATER

大于

NO_OP

排除所有


 

Comparator

Description

BinaryComparator

使用Bytes.compareTo()比较

BinaryPrefixComparator

和BinaryComparator差不多,从前面开始比较

NullComparator

Does not compare against an actual value but whether a given one is null, or not null.

BitComparator

Performs a bitwise comparison, providing a BitwiseOp class with AND, OR, and XOR operators.

RegexStringComparator

正则表达式

SubstringComparator

把数据当成字符串,用contains()来判断



下面是相关比较符的例子

点击(此处)折叠或打开

package com.hxl;

import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.filter.BinaryComparator;
import org.apache.hadoop.hbase.filter.CompareFilter;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.filter.RowFilter;
import org.apache.hadoop.hbase.util.Bytes;

import com.hxl.ConnectDB;

public class RowFilterTest {

    public void rowfilter(String tablename, String rowkeyvalue) {
        Configuration configuration = null;
        configuration = new ConnectDB().getConf();

        try {
            HTable table = new HTable(configuration, tablename);

            Filter filter1 = new RowFilter(CompareFilter.CompareOp.EQUAL,
                    new BinaryComparator(Bytes.toBytes(rowkeyvalue)));
            // EQUAL =

            Scan s = new Scan();
            s.setFilter(filter1);
            ResultScanner rs = table.getScanner(s);

            for (Result r : rs) {
                System.out.println("rowkey:" + new String(r.getRow()));
                for (KeyValue keyValue : r.raw()) {
                    System.out.println("列族:" + new String(keyValue.getFamily())
                            + " 列:" + new String(keyValue.getQualifier()) + ":"
                            + new String(keyValue.getValue()));
                }
            }

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();

        }

    }

}

相关的过滤方法使用:
提取rowkey以01结尾数据
Filter filter = new RowFilter(CompareFilter.CompareOp.EQUAL,new RegexStringComparator(".*01$"));

提取rowkey以包含201407的数据
Filter filter = new RowFilter(CompareFilter.CompareOp.EQUAL,new SubstringComparator("201407"));

提取rowkey以123开头的数据
Filter filter = new RowFilter(CompareFilter.CompareOp.EQUAL,new BinaryPrefixComparator("123".getBytes()));
 

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