HBase开发： Java API 管理表

package step1;

import java.util.ArrayList;
import java.util.List;

import org.apache.hadoop.conf.*;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.*;

public class Task {

	public void showTableList() throws Exception {
		/********* Begin *********/
		Configuration conf = HBaseConfiguration.create(); //使用create()静态方法就可以得到Configuration对象
		Connection conn = ConnectionFactory.createConnection(conf); //config为前文的配置对象
		Admin admin = conn.getAdmin(); //使用连接对象获取Admin对象
		List<TableDescriptor> tableDescriptors = admin.listTableDescriptors();
		for(TableDescriptor tableDescriptor: tableDescriptors){
			System.out.println("Table：" + tableDescriptor.getTableName());
			System.out.println("\texists：" + admin.tableExists(tableDescriptor.getTableName()));
			System.out.println("\tenabled：" + admin.isTableEnabled(tableDescriptor.getTableName()));
		}
		



		/********* End *********/
	}
}

	package step2;

import java.io.IOException;


import org.apache.hadoop.conf.*;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.io.compress.Compression;
import org.apache.hadoop.hbase.util.*;

public class Task {
	
	public void updateTables()throws Exception{
		/********* Begin *********/
		Configuration conf = HBaseConfiguration.create(); //使用create()静态方法就可以得到Configuration对象
		Connection conn = ConnectionFactory.createConnection(conf); //config为前文的配置对象
		Admin admin = conn.getAdmin(); //使用连接对象获取Admin对象
		TableName tableName1 = TableName.valueOf("t_emp2");
		TableName tableName2 = TableName.valueOf("t_dept2");
				ColumnFamilyDescriptorBuilder buildFamily = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes("data"));//创建builder对象
				buildFamily.setBlocksize(1024*1024);//设置缓存大小
				buildFamily.setBlockCacheEnabled(false);//设置关闭缓存，默认是true
				buildFamily.setCompressionType(Compression.Algorithm.GZ);//默认是NONE
				ColumnFamilyDescriptor family = buildFamily.build();//构建Family对象
				admin.modifyColumnFamily(tableName1, family);//调用修改方法，方法接收两个参数：TableName，ColumnFamilyDescriptor
				admin.deleteColumnFamily(tableName1, Bytes.toBytes("data1"));//删除表中名为data的列族    
			
			
				ColumnFamilyDescriptorBuilder buildFamily1 = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes("data1"));//创建builder对象
				buildFamily1.setMinVersions(2);
				buildFamily1.setMaxVersions(5);
				buildFamily1.setInMemory(true); //默认是false
				buildFamily1.setTimeToLive(60*60*24); //以秒为单位，超过这个时间设置的就会在下一次大合并中被删除
				ColumnFamilyDescriptor family1 = buildFamily1.build();//构建Family对象
				admin.modifyColumnFamily(tableName2, family1);//调用修改方法，方法接收两个参数：TableName，ColumnFamilyDescriptor

				admin.deleteColumnFamily(tableName2, Bytes.toBytes("data"));//删除表中名为data的列族  
		
			







		/********* End *********/
	}
	
}

package step3;

import java.io.IOException;

import org.apache.hadoop.conf.*;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.*;


public class Task {

	/**
	 * 刪除表
	 * @param tableName 表名
	 * @throws Exception
	 */
	public void deleteTable(String tableName)throws Exception{
		/********* Begin *********/
		Configuration conf = HBaseConfiguration.create(); //使用create()静态方法就可以得到Configuration对象
		Connection conn = ConnectionFactory.createConnection(conf); //config为前文的配置对象
		Admin admin = conn.getAdmin(); //使用连接对象获取Admin对象
		TableName testName = TableName.valueOf(Bytes.toBytes(tableName));
		admin.disableTable(testName);
		admin.deleteTable(testName);
	


		/********* End *********/
	}
	
	/**
	 * 创建表
	 * @param tableName  表名
	 * @param columnNames 列族的动态数组
	 * @throws Exception
	 */
	public void createTable(String tableName,String... columnNames)throws Exception{
		/********* Begin *********/
		Configuration conf = HBaseConfiguration.create(); //使用create()静态方法就可以得到Configuration对象
		Connection conn = ConnectionFactory.createConnection(conf); //config为前文的配置对象
		Admin admin = conn.getAdmin(); //使用连接对象获取Admin对象

		// TableName tableName1 = TableName.valueOf(Bytes.toBytes(tableName));//定义表名
		// HTableDescriptor htd = new HTableDescriptor(tableName1);//定义表对象
		// for(String s: columnNames){
		// 	htd.addFamily(new HColumnDescriptor(Bytes.toBytes(s)));
		// }

        //构建一个Test_teacher_info表
        TableDescriptorBuilder test_teacher_info = TableDescriptorBuilder.newBuilder(TableName.valueOf(tableName));

        for(String s: columnNames){
			ColumnFamilyDescriptor of = ColumnFamilyDescriptorBuilder.of(s);
 			test_teacher_info.setColumnFamily(of);
		}
    
        //构建
        TableDescriptor build = test_teacher_info.build();
 
        admin.createTable(build);



		/********* End *********/
	}
	
	/**
	 * 启用表
	 * @param tableName 
	 * @throws Exception 
	 */
	public void enableTable(String tableName) throws Exception{
		/********* Begin *********/
		Configuration conf = HBaseConfiguration.create(); //使用create()静态方法就可以得到Configuration对象
		Connection conn = ConnectionFactory.createConnection(conf); //config为前文的配置对象
		Admin admin = conn.getAdmin(); //使用连接对象获取Admin对象
		TableName demoName = TableName.valueOf(Bytes.toBytes(tableName));
		admin.enableTable(demoName);


		/********* End *********/
	}
	
	/**
	 * 禁用表
	 * @param tableName
	 */
	public void disableTable(String tableName)throws Exception{
		/********* Begin *********/
		Configuration conf = HBaseConfiguration.create(); //使用create()静态方法就可以得到Configuration对象
		Connection conn = ConnectionFactory.createConnection(conf); //config为前文的配置对象
		Admin admin = conn.getAdmin(); //使用连接对象获取Admin对象
		TableName testName = TableName.valueOf(Bytes.toBytes(tableName));
		admin.disableTable(testName);


		/********* End *********/
	}
	
}