HBase Java API使用操作例子

通过对HBase API的使用，下面例子举例了常见对HBase的操作，如下所示：

package net.linuxidc.www;  
-
 

  
import org.apache.Hadoop.conf.Configuration;  
import org.apache.hadoop.hbase.HBaseConfiguration;  
import org.apache.hadoop.hbase.HColumnDescriptor;  
import org.apache.hadoop.hbase.HTableDescriptor;  
import org.apache.hadoop.hbase.KeyValue;  
import org.apache.hadoop.hbase.client.HBaseAdmin;  
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.io.BatchUpdate;  
  
public class HBaseDBDao {  
      
    //定义配置对象HBaseConfiguration   
    static HBaseConfiguration cfg =null;  
    static {  
        Configuration configuration = new Configuration();  
        cfg = new HBaseConfiguration(configuration);  
    }  
      
    //创建一张表，指定表名，列族   
    public static void createTable(String tableName,String columnFarily)throws Exception{  
        HBaseAdmin admin = new HBaseAdmin(cfg);  
        if(admin.tableExists(tableName)){  
            System.out.println(tableName+"不存在！");  
            System.exit(0);  
        }else{  
            HTableDescriptor  tableDesc = new HTableDescriptor(tableName);  
            tableDesc.addFamily(new HColumnDescriptor(columnFarily+":"));  
            System.out.println("创建表成功！");  
        }  
    }  
      
    //添加数据，通过HTable。和BatchUpdate为已经存在的表添加数据data   
    public static void addData(String tableName,String row,String columnFamily,String column,String data)throws Exception{  
        HTable table = new HTable(cfg,tableName);  
        BatchUpdate update = new BatchUpdate(row);  
        update.put(columnFamily+":"+column, data.getBytes());  
        table.commit(update);  
        System.out.println("添加成功！");  
    }  
      
    //显示所有数据，通过HTable Scan类获取已有表的信息   
    public static void getAllData(String tableName)throws Exception{  
        HTable table = new HTable(cfg,tableName);  
        Scan scan = new Scan();  
        ResultScanner rs = table.getScanner(scan);  
        for(Result r:rs){  
            for(KeyValue kv:r.raw()){  
                System.out.println(new String(kv.getColumn())+new String(kv.getValue()));  
            }  
        }  
    }  
      
    //测试函数   
    public static void main(String[] args){  
        try{  
            String tableName = "student";  
            HBaseDBDao.createTable(tableName, "c1");  
            HBaseDBDao.addData(tableName, "row1", "c1", "1", "this is row 1 column c1:c1");  
            HBaseDBDao.getAllData(tableName);  
        }catch(Exception e){  
            e.printStackTrace();  
        }  
    }  
} 

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