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???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();

}

}

}