java實現Hbase中的查詢(一)Filter方式

weixin_34377065發表於2012-08-23

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、已有表結構:

1、表名:scores

2、列族:

course:art

course:math

grade:

   

3、scan 'scores'的內容:

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、程式碼:

[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,通過rowKey查詢 
  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,通過rowKey、column查詢 
  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){ // 各個條件之間是“與”的關係  
  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.             // 新增下面這一行後,則只返回指定的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查詢,查詢Tom行的所有cell  
  93.         HBaseBasic03.selectByRowKey("scores","Tom");  
  94.           
  95.         // 按rokey 和 column 來查詢,查詢Tom行course列族的所有列值  
  96.         HBaseBasic03.selectByRowKeyColumn("scores","Tom","course");  
  97.           
  98.         // Filter多條件查詢,條件:查詢 course列族中art列值為97 ,且 course列族中math列值為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.       

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