Java操作HBase的基本用法

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一、在maven工程中加入Hbase的依赖

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<dependency>
	<groupId>org.apache.hbase</groupId>
	<artifactId>hbase-client</artifactId>
	<version>0.98.8-hadoop2</version>
</dependency>
<dependency>
	<groupId>org.apache.hbase</groupId>
	<artifactId>hbase-server</artifactId>
	<version>0.98.8-hadoop2</version>
</dependency>

二、将hbase-site.xml放入src/main/resources目录下

三、确保HDFS、YARN、HBase都正常启动

四、编写代码

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/*
 * HBaseTest.java
 *
 *  Created on: 2016年4月10日 下午4:30:48
 *      Author: Wayne 13186259527@163.com
 */
package HBase;

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.KeyValue;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.TableName;
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.HTableInterface;
import org.apache.hadoop.hbase.client.HTablePool;
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;

/**
 * @author Administrator
 *
 */
public class HBasetest {
	static HBaseAdmin admin = null;
	Configuration conf = null;

	/**
	 * 构造函数初始化加载
	 */
	public HBasetest() throws MasterNotRunningException,
			ZooKeeperConnectionException, IOException {
		/**
		 * 前提：要把hbase-site.xml放在src/main/resources目录下
		 */
		conf = HBaseConfiguration.create();
		admin = new HBaseAdmin(conf);
		System.out.println("hbase连接成功！");
	}

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

		HBasetest hBase = new HBasetest();
		// System.out.println(admin);
		//创建表
		hBase.createTable("Tabletest", "info", "scores");
		//插入一条记录
		hBase.addOneData("Tabletest", "one", "info", "weight", "50kg");
		hBase.addOneData("Tabletest", "one", "info", "hight", "175cm");
		//获得所有表中记录
		hBase.getAllData("Tabletest");
		//获得表中一行记录	
		hBase.getOneRcord("Tabletest", "one");
		//删除表中一行记录
		hBase.deleteAllOnedata("Tabletest", "one");
		//删除表中一条记录
		hBase.deleteOneRcord("Tabletest", "one", "info", "hight");
		//删除一个表
		hBase.deleteTable("Tabletest");

		// hBase.getAllTable();
		admin.close();

	}

	/**
	 * @param string
	 * @param string2
	 * @throws IOException
	 */
	private static void createTable(String tableName, String family1,
			String family2) throws IOException {
		if (admin.tableExists(tableName)) {
			System.out.println(tableName + "表已存在");
		} else {
			System.out.println("start to create table");
			HTableDescriptor hTableDescriptor = new HTableDescriptor(
					TableName.valueOf(tableName));
			hTableDescriptor.addFamily(new HColumnDescriptor(family1));
			hTableDescriptor.addFamily(new HColumnDescriptor(family2));
			admin.createTable(hTableDescriptor);
			System.out.println(tableName + "表创建成功！");
		}
	}

	/**
	 * 查询所有记录
	 * 
	 * @param tableName
	 */
	private void getAllData(String tableName) {
		try {
			HTable hTable = new HTable(conf, tableName);
			Scan scan = new Scan();
			ResultScanner scanner = hTable.getScanner(scan);
			for (Result result : scanner) {
				if (result.raw().length > 0) {
					for (KeyValue kv : result.raw()) {
						System.out.println(new String(kv.getRow()) + "\t"
								+ new String(kv.getValue()));
					}
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		}

	}

	/**
	 * 往表中添加一条数据
	 * 
	 * @param tableName
	 * @param rowkey
	 * @param family
	 * @param qualifier
	 * @param value
	 */
	private void addOneData(String tableName, String rowkey, String family,
			String qualifier, String value) {
		HTablePool hTablePool = new HTablePool(conf, 1000);
		HTableInterface table = hTablePool.getTable(tableName);
		Put put = new Put(rowkey.getBytes());
		put.add(family.getBytes(), qualifier.getBytes(), value.getBytes());
		try {
			table.put(put);
			System.out.println("记录" + rowkey + "添加成功！");
		} catch (IOException e) {
			e.printStackTrace();
			System.out.println("记录" + rowkey + "添加失败！");
		}
	}

	/**
	 * 获取所有的列表
	 */
	private void getAllTable() {
		if (admin != null) {
			try {
				HTableDescriptor[] listTables = admin.listTables();
				if (listTables.length > 0) {
					for (HTableDescriptor hTableDescriptor : listTables) {
						System.out.println(hTableDescriptor.getNameAsString());
					}
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	private void getOneRcord(String tableName, String rowkey) {
		HTablePool hTablePool = new HTablePool(conf, 1000);
		HTableInterface table = hTablePool.getTable(tableName);
		Get get = new Get(rowkey.getBytes());
		try {
			Result result = table.get(get);
			if (result.raw().length > 0) {
				for (KeyValue kv : result.raw()) {
					/*
					 * System.out.println(new String(kv.getRow()) + "\t" + new
					 * String(kv.getValue()));
					 */

					System.out.println(new String(kv.getRowArray()) + "\t");
					// + new String(kv.getValueArray()));
					/*
					 * System.out.println(new String(kv.getKey()) + "\t" + new
					 * String(kv.getValue()));
					 */
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 删除一条记录
	 * 
	 * @param string
	 * @param string2
	 */
	private void deleteAllOnedata(String tableName, String rowkey) {
		HTablePool hTablePool = new HTablePool(conf, 1000);
		HTableInterface table = hTablePool.getTable(tableName);
		Delete delete = new Delete(rowkey.getBytes());
		try {
			table.delete(delete);
			System.out.println(rowkey + " 记录删除成功！");
		} catch (IOException e) {
			e.printStackTrace();
			System.out.println(rowkey + " 记录删除失败！");
		}
	}

	/**
	 * 删除一条记录的一个值
	 * 
	 * @param tableName
	 * @param rowkey
	 * @param family
	 * @param qualifier
	 */
	private void deleteOneRcord(String tableName, String rowkey, String family,
			String qualifier) {
		HTablePool hTablePool = new HTablePool(conf, 1000);
		HTableInterface table = hTablePool.getTable(tableName);
		Delete delete = new Delete(rowkey.getBytes());
		delete.deleteColumn(family.getBytes(), qualifier.getBytes());
		try {
			table.delete(delete);
			System.out.println(tableName + " " + rowkey + "," + family + ":"
					+ qualifier + "值删除成功！");
		} catch (IOException e) {
			e.printStackTrace();
			System.out.println(tableName + " " + rowkey + "," + family + ":"
					+ qualifier + "值删除失败s！");
		}

	}

	/**
	 * 删除一张表
	 * 
	 * @param tableName
	 */
	private void deleteTable(String tableName) {
		if (admin != null) {
			try {
				admin.disableTable(tableName);
				admin.deleteTable(tableName);
				System.out.println(tableName + "表删除成功！");
			} catch (IOException e) {
				e.printStackTrace();
				System.out.println(tableName + "表删除失败！");
			}
		}
	}
}

五、遇到的问题

  • 点击运行，可以打印出admin的信息，但是一开始测试的创建表的操作始终不出结果。
    一直等啊，等，等啊，等
    最后终于出了结果：

unknown crxy

crxy 是我的虚拟机的主机名

我一想，可能是主机名没有在windows映射成地址，试试~

打开：C:\Windows\System32\drivers\etc\hosts

增加： 地址 主机名

搞定~

六、追加

上面实现的扫描一张表的实现不完善，没有把表中的每一项（行键、列族、列、值）都显示出来。
下面是更新的方法：

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/*
 * Scanner.java
 *
 *  Created on: 2016年4月10日 下午6:27:10
 *      Author: Wayne 13186259527@163.com
 */
package HBase;

import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
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;

/**
 * @author Administrator
 *
 */
public class Scanner {
	public static void main(String[] args) throws Exception {
		Configuration conf = HBaseConfiguration.create();
		Scan scan = new Scan();
		HTable hTable = new HTable(conf, "test1");
		ResultScanner scanner = hTable.getScanner(scan);
		for (Result result : scanner) {
			/**
			 * 这里用的都是keyValue里面旧的方法来获取行键，列族，列和值
			 * 新的方法后面都有个Array，但是显示出来中间总有乱码，
			 * 我猜测是时间戳在中间，但不知道怎么解析。
			 * 以后再来解决
			 */
			for (KeyValue keyValue : result.raw()) {

				System.out.println("row:"+new String(keyValue.getRow())+
						"\tcolumnfamily:"+ new String(keyValue.getFamily()) + 
						"\tcolumn:"+ new String(keyValue.getQualifier()) + 
						"\tvalue:"+ new String(keyValue.getValue()));
			}
		}
	}
}