HBase之过滤器

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本文介绍了HBase中的各种过滤器，包括行键过滤器、正则过滤器、子串过滤器及列族过滤器等，并提供了具体的使用示例。

Filter的执行过程
过滤器在客户端创建，然后通过RPC协议发送到服务器上，由服务器执行

比较器

[su_table]

Comparator	Description
LongComparator	Assumes the given value array is a Java Long number and uses Bytes.toLong() to convert it.
BinaryComparator	Uses Bytes.compareTo() to compare 当前值与阀值
BinaryPrefixComparator	Bytes.compareTo() 进行匹配，但是从左端开始前缀匹配
NullComparator	判断当前值是否为null
BitComparator	Performs a bitwise comparison, providing a BitwiseOp enumeration with AND, OR, and XOR operators.
RegexStringComparator	正则表达式匹配
SubstringComparator	子字符串比对

[/su_table]

RowFilter 行健过滤器

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.filter.*;
import org.apache.hadoop.hbase.util.Bytes;

import java.io.IOException;

/**
 * 基于行键上的过滤器
 */
public class FilterInHbase {
    public static void main(String[] args) throws IOException{
        Configuration configuration = HBaseConfiguration.create();
        Connection connection = ConnectionFactory.createConnection(configuration);
        //建立user表的连接
        Table table =connection.getTable(TableName.valueOf("user"));
        Scan scan=new Scan();
        //扫描列族info 列age
        scan.addColumn(Bytes.toBytes("info"),Bytes.toBytes("age"));

        System.out.println("行过滤器");
        //比较过滤器
        //这儿是指找出行小于或者等于"510824118261011172"的所有行
        Filter filter1 = new RowFilter(CompareFilter.CompareOp.LESS_OR_EQUAL, new BinaryComparator(Bytes.toBytes("813782218261011172")));
        //添加过滤器到扫描器中
        scan.setFilter(filter1);
        ResultScanner scanner1 = table.getScanner(scan);
        for(Result res:scanner1){
            System.out.println(res);
        }
        scanner1.close();

        System.out.println("正则过滤器");
        //正则过滤器
        //过滤行键以2结束的
        Filter filter2 = new RowFilter(CompareFilter.CompareOp.EQUAL,
                new RegexStringComparator(".*2$")
                );
        scan.setFilter(filter2);
        ResultScanner scanner2 = table.getScanner(scan);
        for (Result res:scanner2){
            System.out.println(res);
        }
        scanner2.close();

        //子串过滤器
        //过滤行键中包含了"61826"这个字符串
        System.out.println("子串过滤器");
        Scan scan3=new Scan();
        //扫描列族info 列age
        scan3.addColumn(Bytes.toBytes("info"),Bytes.toBytes("age"));
        Filter filter3=new RowFilter(CompareFilter.CompareOp.EQUAL,
                new SubstringComparator("61826")
                );
        scan3.setFilter(filter3);
        ResultScanner scanner3=table.getScanner(scan3);
        for(Result res:scanner3){
            System.out.println(res);
        }
        scanner3.close();

        table.close();
        connection.close();
    }
}

/**
Result:

 行过滤器 < 813782218261011172
 keyvalues={224382618261914241/info:age/1472196211169/Put/vlen=2/seqid=0}
 keyvalues={510824118261011172/info:age/1472196213020/Put/vlen=2/seqid=0}
 keyvalues={524382618264914241/info:age/1472196193913/Put/vlen=2/seqid=0}
 keyvalues={673782618261019142/info:age/1472196211733/Put/vlen=2/seqid=0}
 keyvalues={813782218261011172/info:age/1472196212550/Put/vlen=2/seqid=0}
 正则过滤器 已2结尾的行键
 keyvalues={510824118261011172/info:age/1472196213020/Put/vlen=2/seqid=0}
 keyvalues={673782618261019142/info:age/1472196211733/Put/vlen=2/seqid=0}
 keyvalues={813782218261011172/info:age/1472196212550/Put/vlen=2/seqid=0}
 子串过滤器 包含了"61826"的行键
 keyvalues={224382618261914241/info:age/1472196211169/Put/vlen=2/seqid=0}
 keyvalues={524382618264914241/info:age/1472196193913/Put/vlen=2/seqid=0}
 keyvalues={673782618261019142/info:age/1472196211733/Put/vlen=2/seqid=0}
 **/

FamilyFilter 列族过滤器

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.filter.BinaryComparator;
import org.apache.hadoop.hbase.filter.CompareFilter;
import org.apache.hadoop.hbase.filter.FamilyFilter;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.util.Bytes;
import java.io.IOException;
/**
 * 列族过滤器
 * 比较列族来返回结果
 * 用户可以在列族一级筛选所需数据
 */
public class FamilyFilterInHbase {
    public static void main(String[] args) throws IOException {
        Configuration configuration = HBaseConfiguration.create();
        Connection connection = ConnectionFactory.createConnection(configuration);
        //建立表的连接
        Table table = connection.getTable(TableName.valueOf("user"));

        //比较过滤器 现在表有2个列族 info  ship 当然实际有可能很多哦
        //取info