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, value=87                           
 Tom                         column=grade:, timestamp=1301294629931, value=1

 

4、代码：

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 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 arr=new ArrayList(); arr.add("course,art,97"); arr.add("course,math,100"); HBaseBasic03.selectByFilter("scores",arr); } }