educoder平台HBase高级特性：过滤器(二)

第1关：常用的专用过滤器

package step1;

import java.io.IOException;

import javax.ws.rs.POST;

import org.apache.hadoop.cli.util.*;

import org.apache.hadoop.conf.*;

import org.apache.hadoop.hbase.*;

import org.apache.hadoop.hbase.client.*;

import org.apache.hadoop.hbase.filter.*;

import org.apache.hadoop.hbase.util.*;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.hbase.Cell;

import org.apache.hadoop.hbase.HBaseConfiguration;

import org.apache.hadoop.hbase.TableName;

import org.apache.hadoop.hbase.client.*;

import org.apache.hadoop.hbase.util.Bytes;

import java.io.IOException;

public class Task {

public void query(String tName) throws Exception {

/********* Begin *********/

Configuration config = new Configuration();

Connection conn = ConnectionFactory.createConnection(config);

TableName tableName = TableName.valueOf(Bytes.toBytes("test_tb1"));

Table table = conn.getTable(tableName);

Filter filter = new PrefixFilter(Bytes.toBytes("row5"));

Scan scan = new Scan();

scan.setFilter(filter);

ResultScanner scanner = table.getScanner(scan);

for (Result result : scanner) {

System.out.println(Bytes.toString(result.getRow()));

for(Cell cell : result.listCells()){

String family = Bytes.toString(CellUtil.cloneFamily(cell));

String qualifier = Bytes.toString(CellUtil.cloneQualifier(cell));

String value = Bytes.toString(CellUtil.cloneValue(cell));

System.out.println("\t" + family + ":" + qualifier + " " + value);

}

}

//分页

byte[] POSTFIX = new byte[] {0};

Filter filter1 = new PageFilter(10);//构建过滤器并设置每页数据量

int totalRows = 0;

byte[] lastRow = null;

int i = 4;

while(i > 0 ){

Scan scan1 = new Scan();

//添加过滤器

scan1.setFilter(filter1);

//设置查询的起始行

if(lastRow != null){

byte[] startRow = Bytes.add(lastRow, POSTFIX);

String info = new String(startRow,"utf-8");

System.out.println("开始分页查询");

scan1.withStartRow(startRow);

}

ResultScanner scanner1= table.getScanner(scan1);

int localRows = 0;

Result result;

while ((result = scanner1.next()) != null) {

System.out.println(Bytes.toString(result.getRow()));

for(Cell cell : result.listCells()){

String family = Bytes.toString(CellUtil.cloneFamily(cell));

String qualifier = Bytes.toString(CellUtil.cloneQualifier(cell));

String value = Bytes.toString(CellUtil.cloneValue(cell));

System.out.println("\t" + family + ":" + qualifier + " " + value);

}

localRows++;

totalRows++;

lastRow = result.getRow();

}

scanner1.close();

if (localRows == 0) break;

i--;

}

conn.close();

/********* End *********/

}

}

第2关：同时使用多种过滤器

package step2;

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

import org.apache.hadoop.cli.util.*;

import org.apache.hadoop.conf.*;

import org.apache.hadoop.hbase.*;

import org.apache.hadoop.hbase.client.*;