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