hbase基本操作

转载自：http://blog.sina.com.cn/s/blog_8c6d7ff60100zexn.html

一、HBase JavaAPI：

    1.HbaseConfiguration

    关系：org.apache.hadoop.hbase.HBaseConfiguration

    作用：通过此类可以对HBase进行配置

    2.HBaseAdmin

     关系：org.apache.hadoop.hbase.client.HBaseAdmin

    作用：提供一个接口来管理HBase数据库中的表信息。它提供创建表、删除表等方法。

   3.HTableDescriptor

    关系：org.apache.hadoop.hbase.client.HTableDescriptor

    作用：包含了表的名字及其对应列族。 提供的方法有

       void               addFamily(HColumnDescriptor)             添加一个列族

       HColumnDescriptor  removeFamily(byte[]column)              移除一个列族

       byte[]             getName()                                 获取表的名字

       byte[]             getValue(byte[]key)                      获取属性的值

       void               setValue(String key,Stringvalue)        设置属性的值

    4.HColumnDescriptor

     关系：org.apache.hadoop.hbase.client.HColumnDescriptor

     作用：维护关于列的信息。提供的方法有

       byte[]              getName()                                 获取列族的名字

       byte[]             getValue()                                获取对应的属性的值

       void               setValue(String key,Stringvalue)        设置对应属性的值

   5.HTable

     关系：org.apache.hadoop.hbase.client.HTable

      作用：用户与HBase表进行通信。此方法对于更新操作来说是非线程安全的，如果启动多个线程尝试与单个HTable实例进行通信，那么写缓冲器可能会崩溃。

   6.Put

     关系：org.apache.hadoop.hbase.client.Put

     作用：用于对单个行执行添加操作

   7.Get

     关系：org.apache.hadoop.hbase.client.Get

     作用：用于获取单个行的相关信息

   8.Result

      关系：org.apache.hadoop.hbase.client.Result

      作用：存储Get或Scan操作后获取的单行值。

   9.ResultScanner

     关系：Interface

     作用：客户端获取值的接口。

二、示例：

　以下是一个完整的代码示例，基于hbase-0.90.3编写

类：HBaseOperation 功能： 创建、删除表，增加、删除、查询记录。

类：HBaseTest      功能： 实例化HBaseOperation，使用其相应方法。

2.1HBaseOperation源码如下：

 

package model;

 

 

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

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.client.Delete;

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;

 

 

public class HBaseOperation {

  //.相关属性

  private  Configurationconf ;

  private  HBaseAdminadmin;

  

  public HBaseOperation(Configuration conf) throws IOException{

     this.conf=HBaseConfiguration.create(conf);

     this.admin =new HBaseAdmin(this.conf);

  }

  public HBaseOperation()throws IOException{

     Configuration cnf = new Configuration();

     this.conf=HBaseConfiguration.create(cnf);

     this.admin=new HBaseAdmin(this.conf);

  }

  

  //1.创建表

  public void  createTable(StringtableName,String colFamilies[]) throws IOException{

 

        if(this.admin.tableExists(tableName)){

           System.out.println("Table: "+tableName+" already exists!");

        }else{

           HTableDescriptor dsc = new HTableDescriptor(tableName);

           int len = colFamilies.length;

           for(int i=0;i<len;i++){

              HColumnDescriptor family = new HColumnDescriptor(colFamilies[i]);

              dsc.addFamily(family);

           }

           admin.createTable(dsc);

           System.out.println("创建表成功");

        }

  }

  //2.删除表

  public void deleteTable(String tableName)throws IOException{

        if(this.admin.tableExists(tableName)){

           admin.deleteTable(tableName);

           System.out.println("删除表成功");

        }else{

           System.out.println("Table Not Exists!");

        }

  }

  //3.插入一行记录

  public void insertRecord(String tableName,Stringrowkey,String family,String qualifier,String value)throws IOException {

  

        HTable table = new HTable(this.conf,tableName);

        Put  put= new Put(rowkey.getBytes());

       put.add(family.getBytes(),qualifier.getBytes(),value.getBytes());

        table.put(put);

        

        System.out.println("插入行成功");

  }

  //4.删除一行记录

  public void deleteRecord(String tableName,Stringrowkey) throws IOException{

     

        HTable table = new HTable(this.conf,tableName);

        Delete del =new Delete(rowkey.getBytes());

        table.delete(del);

        System.out.println("删除行成功");

  }

  //5.获取一行记录

  public Result getOneRecord(StringtableName,String rowkey) throws IOException{

        HTable table =new HTable(this.conf,tableName);

        Get get =new Get(rowkey.getBytes());    

        Result rs = table.get(get); 

        return rs;

  }

  //6.获取所有记录

   public List<Result>getAllRecord(String tableName) throws IOException{

             

     HTable table = new HTable(this.conf,tableName);

      Scanscan = new Scan();

     ResultScanner scanner =table.getScanner(scan);

     List<Result> list=new ArrayList<Result>();

      for(Result r:scanner){ 

        list.add(r);

      }

      scanner.close();

      return list;    

   }

}

 

 

2.2HBaseTest源码如下：

package model;

 

import java.io.IOException;

import java.util.Iterator;

import java.util.List;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.hbase.KeyValue;

import org.apache.hadoop.hbase.client.Result;

public class HBaseTest {

 

   public static void main(String[] args)throws IOException {

 

      // TODO Auto-generated methodstub

      System.out.println("hello veagle and serapy  ");

 

//1.初始化HBaseOperation

      

      Configuration conf = new Configuration();

       //与hbase/conf/hbase-site.xml中hbase.zookeeper.quorum配置的值相同   

       conf.set("hbase.zookeeper.quorum", "172.21.7.124"); 

       //与hbase/conf/hbase-site.xml中hbase.zookeeper.property.clientPort配置的值相同  

       conf.set("hbase.zookeeper.property.clientPort", "2181"); 

      HBaseOperation hbase = new HBaseOperation(conf);

 

//2.测试相应操作

 

      //2.1创建表

 

      String tableName = "blog";

      String colFamilies[]={"article","author"};

      hbase.createTable(tableName, colFamilies);

 

      //2.2插入一条记录

 

      hbase.insertRecord(tableName, "row1", "article", "title", "Hadoop");

      hbase.insertRecord(tableName, "row1", "author", "name", "veagle");

     hbase.insertRecord(tableName, "row1", "author", "nickname", "serapy");

 

      //2.3查询一条记录

 

      Result rs1 =hbase.getOneRecord(tableName, "row1");

 

      for(KeyValue kv:rs1.raw()){

          System.out.println(new String(kv.getRow()));

          System.out.println(new String(kv.getFamily()));

          System.out.println(new String(kv.getQualifier()));

          System.out.println(new String(kv.getValue()));

      }

 

      //2.4查询整个Table

 

      List<Result>list =null;

      list= hbase.getAllRecord("blog"); 

      Iterator<Result>it = list.iterator();

      

      while(it.hasNext()){

          Resultrs2=it.next();

          for(KeyValue kv :rs2.raw()){

             System.out.print("row key is : " + new String(kv.getRow()));

             System.out.print("family is  : "+ new String(kv.getFamily()));

             System.out.print("qualifier is:" + new String(kv.getQualifier()));

             System.out.print("timestamp is:" +kv.getTimestamp());

             System.out.println("Value  is  : "+ new String(kv.getValue()));

          }

      }

   }

}

 

 

2.3执行结果

插入行成功

插入行成功

插入行成功

row1

article

title

Hadoop

row1

author

name

veagle

row1

author

nickname

serapy

row key is : row1familyis  :articlequalifier is:titletimestampis:1322728761046Value is  :Hadoop

row key is : row1familyis  :authorqualifier is:nametimestamp is:1322728761056Value  is  :veagle

row key is : row1familyis  :authorqualifier is:nicknametimestampis:1322728761060Value  is  :serapy