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：

[java:nogutter] view plaincopy

1. package org.myhbase;  
2.   
3. import java.io.IOException;  
4. import java.util.ArrayList;  
5. import java.util.List;  
6.   
7. import org.apache.hadoop.conf.Configuration;  
8. import org.apache.hadoop.hbase.HBaseConfiguration;  
9. import org.apache.hadoop.hbase.KeyValue;  
10. import org.apache.hadoop.hbase.client.Get;  
11. import org.apache.hadoop.hbase.client.HTable;  
12. import org.apache.hadoop.hbase.client.Result;  
13. import org.apache.hadoop.hbase.client.ResultScanner;  
14. import org.apache.hadoop.hbase.client.Scan;  
15. import org.apache.hadoop.hbase.filter.FilterList;  
16. import org.apache.hadoop.hbase.filter.SingleColumnValueFilter;  
17. import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;  
18. import org.apache.hadoop.hbase.io.Cell;  
19. import org.apache.hadoop.hbase.util.Bytes;  
20.   
21. public class HBaseBasic03 {  
22.     private static HBaseConfiguration hbaseConfig=null;  
23.     static{  
24.         Configuration config=new Configuration();  
25.         config.set("hbase.zookeeper.quorum","192.168.10.149,192.168.10.44,192.168.10.49");  
26.         config.set("hbase.zookeeper.property.clientPort", "2181");  
27.         hbaseConfig=new HBaseConfiguration(config);  
28.     }  
29.       
30.     /** 
31.      * get方式，通过rowKey查询 
32.      * @param tablename 
33.      * @param rowKey 
34.      * @throws IOException 
35.      */  
36.     public static void selectByRowKey(String tablename,String rowKey) throws IOException{  
37.         HTable table=new HTable(hbaseConfig,tablename);  
38.         Get g = new Get(Bytes.toBytes(rowKey));  
39.         Result r=table.get(g);  
40.         for(KeyValue kv:r.raw()){  
41.             System.out.println("column: "+new String(kv.getColumn()));  
42.             System.out.println("value: "+new String(kv.getValue()));  
43.         }  
44.     }  
45.       
46.     /** 
47.      * get方式，通过rowKey、column查询 
48.      * @param tablename 
49.      * @param rowKey 
50.      * @param column 
51.      * @throws IOException 
52.      */  
53.     public static void selectByRowKeyColumn(String tablename,String rowKey,String column) throws IOException{  
54.         HTable table=new HTable(hbaseConfig,tablename);  
55.         Get g = new Get(Bytes.toBytes(rowKey));  
56.         g.addColumn(Bytes.toBytes(column));  
57.         Result r=table.get(g);  
58.         for(KeyValue kv:r.raw()){  
59.             System.out.println("column: "+new String(kv.getColumn()));  
60.             System.out.println("value: "+new String(kv.getValue()));  
61.         }  
62.     }  
63.       
64.       
65.     public static void selectByFilter(String tablename,List<String> arr) throws IOException{  
66.         HTable table=new HTable(hbaseConfig,tablename);  
67.         FilterList filterList = new FilterList();  
68.         Scan s1 = new Scan();  
69.         for(String v:arr){ // 各个条件之间是“与”的关系  
70.             String [] s=v.split(",");  
71.             filterList.addFilter(new SingleColumnValueFilter(Bytes.toBytes(s[0]),  
72.                                                              Bytes.toBytes(s[1]),  
73.                                                              CompareOp.EQUAL,Bytes.toBytes(s[2])  
74.                                                              )  
75.             );  
76.             // 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  
77. //          s1.addColumn(Bytes.toBytes(s[0]), Bytes.toBytes(s[1]));  
78.         }  
79.         s1.setFilter(filterList);  
80.         ResultScanner ResultScannerFilterList = table.getScanner(s1);  
81.         for(Result rr=ResultScannerFilterList.next();rr!=null;rr=ResultScannerFilterList.next()){  
82.             for(KeyValue kv:rr.list()){  
83.                 System.out.println("row : "+new String(kv.getRow()));  
84.                 System.out.println("column : "+new String(kv.getColumn()));  
85.                 System.out.println("value : "+new String(kv.getValue()));  
86.             }  
87.         }  
88.     }  
89.       
90.     public static void main(String [] args) throws IOException{  
91.           
92.         // 按rowkey查询，查询Tom行的所有cell  
93.         HBaseBasic03.selectByRowKey("scores","Tom");  
94.           
95.         // 按rokey 和 column 来查询，查询Tom行course列族的所有列值  
96.         HBaseBasic03.selectByRowKeyColumn("scores","Tom","course");  
97.           
98.         // 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  
99.         List<String> arr=new ArrayList<String>();  
100.         arr.add("course,art,97");  
101.         arr.add("course,math,100");  
102.         HBaseBasic03.selectByFilter("scores",arr);  
103.           
104.     }  
105.       
106. }