HBASE操作(2)-JAVA API

安装

0.安装 Eclipse
1.打开 Eclipse,新建 JAVA 项目

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2.在项目中点属性,选择JAVA Build Path\Libraries,点添加扩展 jar 包

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3.把这些目录下的 jar 包都添加进去

hbase 
hbase\lib 
hadoop 
hadoop\lib

4.修改 Eclipse 所在系统的 hosts 文件
修改C:\Windows\system32\drivers\etc\hosts文件

添加如下内容
xxx.xxx.xxx.xxx hadoop0 xxx.xxx.xxx.xxx hadoop1 xxx.xxx.xxx.xxx hadoop2

5.完成安装,开始写代码

使用

举例:

• import

import java.io.IOException; 

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.ZooKeeperConnectionException; 
import org.apache.hadoop.hbase.client.Get; 
import org.apache.hadoop.hbase.client.HBaseAdmin; 
import org.apache.hadoop.hbase.client.HTable; 
import org.apache.hadoop.hbase.client.Put; 
import org.apache.hadoop.hbase.client.Result; 
import org.apache.hadoop.hbase.client.ResultScanner; 
import org.apache.hadoop.hbase.client.Scan;

• demo 数据

public static final String TABLE_NAME = "users" ; 
public static final String FAMILY_NAME = "info" ; 
public static final String COLUMN_NAME = "age" ; 
public static final String ROW_KEY = "xiaoming" ;

• 设置 HBase 连接

//HBase设置（集群） 
        private static Configuration getConfiguration() { 
              Configuration conf = HBaseConfiguration. create(); 
               conf.set( "hbase.rootdir" , "hdfs://hadoop0:9000/hbase" ); 
               conf.set( "hbase.zookeeper.quorum" , "hadoop0,hadoop1,hadoop2" ); 
               return conf ; 
       }

• 创建表

//创建表      
private static void createTabele(HBaseAdmin hbaseAdmin) throws IOException { 

               if (!hbaseAdmin .tableExists( TABLE_NAME)) { 
                     HTableDescriptor hTableDescriptor = new HTableDescriptor(TABLE_NAME ); 
                     HColumnDescriptor hColumnDescriptor = new HColumnDescriptor( 
                                   FAMILY_NAME ); 

                      hTableDescriptor .addFamily(hColumnDescriptor ); 
                      hbaseAdmin .createTable(hTableDescriptor ); 
              } 

       }

• 插入或修改记录

//插入或修改记录 
        private static void putRecord(HTable htable) throws IOException { 
               // TODO Auto-generated method stub 
              Put put = new Put(ROW_KEY .getBytes()); 
               put.add( FAMILY_NAME .getBytes(), COLUMN_NAME.getBytes(), "25" .getBytes()); 
               htable.put( put); 
              System. out .println("insert or update a record" ); 

       } 

        //插入或修改记录2 
        private static void putRecord2(HTable htable, String val) 
                      throws IOException { 
               // TODO Auto-generated method stub 
              Put put = new Put(ROW_KEY .getBytes()); 
               put.add( FAMILY_NAME .getBytes(), COLUMN_NAME.getBytes(), val .getBytes()); 
               htable.put( put); 
              System. out .println("insert or update a record" ); 

       }

• 读取记录   
  

//读取记录
        private static void getRecord(HTable htable) throws Throwable { 

              Get get = new Get(ROW_KEY .getBytes()); 
              Result result = htable.get( get); 
               byte [] value = result .getValue( FAMILY_NAME.getBytes(), 
                            COLUMN_NAME .getBytes()); 
              System. out .println("查询结果为:" + new String( value)); 

       }

• 显示所有记录

//显示所有记录
        private static void scanTable(HTable htable) throws IOException { 
               // TODO Auto-generated method stub 
              System. out .println("遍历表结果如下：" ); 
              Scan scan = new Scan(); 

              ResultScanner resultScanner = htable .getScanner( scan); 
               for (Result result : resultScanner ) { 

                      //遍历数据 
//                   byte[] value = result.getValue(FAMILY_NAME.getBytes(), 
//                                COLUMN_NAME.getBytes()); 
//                   System.out.println(new String(value)); 

                     System. out .println("Scan: " + result ); 

              } 

       }

• 删除表

//删除表
        private static void dropTabele(HBaseAdmin hbaseAdmin ) throws Throwable { 
               if (hbaseAdmin .tableExists( TABLE_NAME)) { 
                      try { 
                            hbaseAdmin .disableTable( TABLE_NAME); 
                            hbaseAdmin .deleteTable( TABLE_NAME); 
                     } catch (IOException e ){ 
                            e.printStackTrace(); 
                           System. out .println("Delete " + hbaseAdmin + "失败" ); 
                     } 
              } 
              System. out .println("Delete " + hbaseAdmin + "成功" ); 
       } 

}