HBase的API以及基本使用

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创建表

package com.zyd.api;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.HTable;
import org.junit.Before;
import org.junit.Test;

public class HBaseApi {
	//创建连接的时候比较慢,可以设置一个连接池
	private HBaseAdmin admin = null;
	private HTable table = null;
	private String TABLE_NAME = "hbaseApi";
	
	//初始化
	@Before
	public void init() throws MasterNotRunningException, ZooKeeperConnectionException, IOException{
		Configuration conf = new Configuration();
		//连接zookeeper,因为zookeeper知道HMaster地址 第一个是在hbase-site.xml文件中
		conf.set("hbase.zookeeper.quorum","note01,note02,note03");
		admin =	new HBaseAdmin(conf);
		
		table = new HTable(conf, TableName.valueOf(TABLE_NAME));
		
	} 
	@Test
	public void createTable() throws IOException{
		HTableDescriptor hTableDescriptor = new HTableDescriptor(TableName.valueOf(TABLE_NAME));
		
		//列族
		HColumnDescriptor hColumnDescriptor1 = new HColumnDescriptor("cf1");
		HColumnDescriptor hColumnDescriptor2 = new HColumnDescriptor("cf2");
		//设置最大版本号,默认是1
		hColumnDescriptor1.setMaxVersions(3);
//		设置生命周期 默认单位为秒
//		hColumnDescriptor1.setTimeToLive(0);
		//add 表示可以创建多个
		hTableDescriptor.addFamily(hColumnDescriptor1);
		hTableDescriptor.addFamily(hColumnDescriptor2);
		
		admin.createTable(hTableDescriptor);
	}
}

结果通过主页http://note03:60010/master-status 访问tables

添加rowkey column value

	//添加数据
	@Test
	public void put() throws RetriesExhaustedWithDetailsException, InterruptedIOException{
	//rowkey
	Put put = new Put("1000".getBytes());
	//列族  列名 value
	put.add("cf1".getBytes(),"name".getBytes(), "zs".getBytes());
	
	put.add("cf1".getBytes(),"age".getBytes(), "18".getBytes());
	
//	table.put(put);
	
	
	Put put2 = new Put("100".getBytes());
	//列族  列名 value
	put2.add("cf1".getBytes(),"name".getBytes(), "zs".getBytes());
	
	put2.add("cf1".getBytes(),"age".getBytes(), "18".getBytes());
	
	
	List<Put> list = new ArrayList<Put>();
	list.add(put);
	list.add(put2);
	//也可以是批量的插入
	table.put(list);
	}

查询

//查询数据
	@Test
	public void get() throws IOException{
		//获取行
		Get get = new Get("100".getBytes());
		
		Result result = table.get(get);
		
		byte[] value = result.getValue("cf1".getBytes(), "name".getBytes());
	
		Cell cell =  result.getColumnLatestCell("cf1".getBytes(),"name".getBytes());
		//可以得到列族名以及其他的信息等
		byte [] cloneFamily = CellUtil.cloneFamily(cell);
		//hbase里面全是字节 自己要知道类型
		String str = new String(value);
		System.out.println(str);
		
		System.out.println("第二种方式:"+new String(cloneFamily));
		//动态添加列时,获取类名方法和value
		List<Cell> listCells = result.listCells();
		
		for (Cell cell2 : listCells) {
			System.out.println("列名(column)"+new String(CellUtil.cloneQualifier(cell2))+"  value"
					+ ":"+new String(CellUtil.cloneValue(cell2)));
		}
	}

扫描

//扫描
	@Test
	public void scan() throws IOException{
		Scan scan = new Scan();
		ResultScanner scanner = table.getScanner(scan);
		
		for (Result result : scanner) {
			List<Cell> lisCells = result.listCells();
			
			for (Cell cell : lisCells) {
				System.out.println("column:"+new String(CellUtil.cloneQualifier(cell))+"  value"
						+ new String(CellUtil.cloneValue(cell)));
			}
		}
	}

出现小bug column 打印的是地址值,
解决:new String()括号位置不正确