java实现Hbase中的查询（一）Filter方式

1、需要的jar包：

commons-codec-1.4.jar

commons-logging-1.0.4.jar

hadoop-0.20.2-core.jar

hbase-0.20.6.jar

log4j-1.2.15.jar

zookeeper-3.2.2.jar

2、已有表结构：

1、表名：scores

2、列族：

course:art

course:math

grade:

3、scan 'scores'的内容：

ROW COLUMN+CELL
Jerry column=course:art, timestamp=1301294630194, value=80
Jerry column=course:math, timestamp=1301294630132, value=100
Jerry column=grade:, timestamp=1301294630073, value=2
Jim column=course:art, timestamp=1301294630363, value=97
Jim column=course:math, timestamp=1301294630305, value=100
Jim column=grade:, timestamp=1301294630247, value=3
Tom column=course:art, timestamp=1301294630015, value=97
Tom column=course:math, timestamp=1301294629987, va
7ff0
lue=87
Tom column=grade:, timestamp=1301294629931, value=1

4、代码：

[java]

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package org.myhbase;

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.hbase.HBaseConfiguration;

import org.apache.hadoop.hbase.KeyValue;

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

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.FilterList;

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

import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;

import org.apache.hadoop.hbase.io.Cell;

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

public class HBaseBasic03 {

private static HBaseConfiguration hbaseConfig=null;

static{

Configuration config=new Configuration();

config.set("hbase.zookeeper.quorum","192.168.10.149,192.168.10.44,192.168.10.49");

config.set("hbase.zookeeper.property.clientPort", "2181");

hbaseConfig=new HBaseConfiguration(config);

}

/**

* get方式，通过rowKey查询

* @param tablename

* @param rowKey

* @throws IOException

*/

public static void selectByRowKey(String tablename,String rowKey) throws IOException{

HTable table=new HTable(hbaseConfig,tablename);

Get g = new Get(Bytes.toBytes(rowKey));

Result r=table.get(g);

for(KeyValue kv:r.raw()){

System.out.println("column: "+new String(kv.getColumn()));

System.out.println("value: "+new String(kv.getValue()));

}

}

/**

* get方式，通过rowKey、column查询

* @param tablename

* @param rowKey

* @param column

* @throws IOException

*/

public static void selectByRowKeyColumn(String tablename,String rowKey,String column) throws IOException{

HTable table=new HTable(hbaseConfig,tablename);

Get g = new Get(Bytes.toBytes(rowKey));

g.addColumn(Bytes.toBytes(column));

Result r=table.get(g);

for(KeyValue kv:r.raw()){

System.out.println("column: "+new String(kv.getColumn()));

System.out.println("value: "+new String(kv.getValue()));

}

}

public static void selectByFilter(String tablename,List<String> arr) throws IOException{

HTable table=new HTable(hbaseConfig,tablename);

FilterList filterList = new FilterList();

Scan s1 = new Scan();

for(String v:arr){ // 各个条件之间是“与”的关系

String [] s=v.split(",");

filterList.addFilter(new SingleColumnValueFilter(Bytes.toBytes(s[0]),

Bytes.toBytes(s[1]),

CompareOp.EQUAL,Bytes.toBytes(s[2])

)

);

// 添加下面这一行后，则只返回指定的cell，同一行中的其他cell不返回

// s1.addColumn(Bytes.toBytes(s[0]), Bytes.toBytes(s[1]));

}

s1.setFilter(filterList);

ResultScanner ResultScannerFilterList = table.getScanner(s1);

for(Result rr=ResultScannerFilterList.next();rr!=null;rr=ResultScannerFilterList.next()){

for(KeyValue kv:rr.list()){

System.out.println("row : "+new String(kv.getRow()));

System.out.println("column : "+new String(kv.getColumn()));

System.out.println("value : "+new String(kv.getValue()));

}

}

}

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

// 按rowkey查询，查询Tom行的所有cell

HBaseBasic03.selectByRowKey("scores","Tom");

// 按rokey 和 column 来查询，查询Tom行course列族的所有列值

HBaseBasic03.selectByRowKeyColumn("scores","Tom","course");

// Filter多条件查询，条件：查询 course列族中art列值为97 ，且 course列族中math列值为100的行

List<String> arr=new ArrayList<String>();

arr.add("course,art,97");

arr.add("course,math,100");

HBaseBasic03.selectByFilter("scores",arr);

}

}