如何通过JAVA客户端访问Hbase

直接上代码

代码块

package com.raiyi.app.dao;
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.KeyValue;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
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;
import org.apache.hadoop.hbase.util.Bytes;
/**
* @author Administrator
*
*/
public class BaseOperation
{

private static final String TABLE_NAME = "userInfo";

public static Configuration conf = null;

public HTable table = null;

public HBaseAdmin admin = null;

static
{
conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum","localhost");
conf.set("hbase.zookeeper.property.clientPort", "2181");
conf.set("zookeeper.session.timeout", "2000");
}

/**
* 创建表
*/
public static void creatTable(String tableName, String[] familys)
throws Exception
{

HBaseAdmin admin = new HBaseAdmin(conf);
if (admin.tableExists(tableName))
{
System.out.println("table already exists!");
}
else
{
HTableDescriptor tableDesc = new HTableDescriptor(tableName);
for (int i = 0; i < familys.length; i++)
{
tableDesc.addFamily(new HColumnDescriptor(familys[i]));
}
admin.createTable(tableDesc);
System.out.println("create table " + tableName + " ok.");
}
}

/**
* 删除表
*/
public static void deleteTable(String tableName)
throws Exception
{

try
{
HBaseAdmin admin = new HBaseAdmin(conf);
admin.disableTable(tableName);
admin.deleteTable(tableName);
System.out.println("delete table " + tableName + " ok.");
}
catch (MasterNotRunningException e)
{
e.printStackTrace();
}
catch (ZooKeeperConnectionException e)
{
e.printStackTrace();
}
}

/**
* 添加记录
*/
public static void addRecord(String tableName, String rowKey, String family, String qualifier,
String value)
throws Exception
{

try
{
HTable table = new HTable(conf, tableName);
Put put = new Put(Bytes.toBytes(rowKey));
put.add(Bytes.toBytes(family), Bytes.toBytes(qualifier), Bytes.toBytes(value));
table.put(put);
System.out.println("insert recored " + rowKey + " to table " + tableName + " ok.");
}
catch (IOException e)
{
e.printStackTrace();
}
}

/**
* 删除记录
*/
public static void delRecord(String tableName, String rowKey)
throws IOException
{

HTable table = new HTable(conf, tableName);
List list = new ArrayList();
Delete del = new Delete(rowKey.getBytes());
list.add(del);
table.delete(list);
System.out.println("del recored " + rowKey + " ok.");
}

/**
* 获取某条记录
*/
public static void getOneRecord(String tableName, String rowKey)
throws IOException
{

HTable table = new HTable(conf, tableName);
Get get = new Get(rowKey.getBytes());
Result rs = table.get(get);
for (KeyValue kv : rs.raw())
{
System.out.print(new String(kv.getRow()) + " ");
System.out.print(new String(kv.getFamily()) + ":");
System.out.print(new String(kv.getQualifier()) + " ");
System.out.print(kv.getTimestamp() + " ");
System.out.println(new String(kv.getValue()));
}
}

/**
* 获取所有记录
*/
public static void getAllRecord(String tableName)
{

try
{
HTable table = new HTable(conf, tableName);
Scan s = new Scan();
ResultScanner ss = table.getScanner(s);
for (Result r : ss)
{
for (KeyValue kv : r.raw())
{
System.out.print(new String(kv.getRow()) + " ");
System.out.print(new String(kv.getFamily()) + ":");
System.out.print(new String(kv.getQualifier()) + " ");
System.out.print(kv.getTimestamp() + " ");
System.out.println(new String(kv.getValue()));
}
}
}
catch (IOException e)
{
e.printStackTrace();
}
}

public static void main(String[] agrs)
{

try
{
String tablename = "scores";
String[] familys =
{
"grade", "course"
};
Long start = System.currentTimeMillis();
//          BaseOperation.creatTable(tablename, familys);

BaseOperation.getOneRecord(tablename, "155226015632015-11");
//
//          System.out.println("===========show all record========");
//          BaseOperation.getAllRecord(tablename);
//
//          System.out.println("===========del one record========");
//          BaseOperation.delRecord(tablename, "baoniu");
//          BaseOperation.getAllRecord(tablename);
//
//          System.out.println("===========show all record========");
//          BaseOperation.getAllRecord(tablename);
System.out.println(System.currentTimeMillis()-start);
}
catch (Exception e)
{
e.printStackTrace();
}
}

}

注意：代码没有什么特殊的地方，但是需要注意 修改程序运行的客户端的hosts文件.对应到hbase运行服务器的ip,比如:192.168.11.111 hbasemaster。

理由: HBase client 初始化连接流程

1.当使用HBase配置创建HTable对象时，最终会得到与RegionServer服务器的连接，使用该连接对RegionServer服务器上的数据操作

2.Client先随机选择连接一台zookeeper建立连接，如果连接建立失败，重新获取与其它zookeeper的连接

3.从zookeeper服务查询region-server主机名，zookeeper会根据RegionServer的负载、状态情况返回一台可用的RegionServer

4.Client端使用该主机名与RegionServer建立连接，如果连接失败，会进行重试，直接到超过重试次数或连接建立成功