熟悉常用的HBASE 操作

package cn.edu.zucc.hbase; 
import java.io.IOException; 
import java.util.Scanner;

import org.apache.hadoop.conf.Configuration; 
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HTableDescriptor; 
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin; 
import org.apache.hadoop.hbase.client.Connection; 
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Delete;
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.client.Table;
import org.apache.hadoop.hbase.util.Bytes;
public class HbasePractice { 
    public static Configuration configuration;
    public static Connection connection; 
    public static Admin admin; 
    //列出所有的表
    public static void listTables() throws IOException 
    { 
        
        HTableDescriptor[] hTableDescriptors = admin.listTables(); 
        for (HTableDescriptor hTableDescriptor : hTableDescriptors) 
        { 
            System.out.println("表名:" + hTableDescriptor.getNameAsString()); 
        }
    }
    //在终端打印出指定的表的所有记录数据
    public static void getData(String tableName) throws IOException 
    { 
        init(); 
        Table table = connection.getTable(TableName.valueOf(tableName)); 
        Scan scan = new Scan(); 
        ResultScanner scanner = table.getScanner(scan); 
        for (Result result : scanner) 
        { 
            printRecoder(result); 
         }
    }

    public static void printRecoder(Result result) throws IOException 
    { 
        for (Cell cell : result.rawCells()) 
        { 
            System.out.print("行健: " + new String(CellUtil.cloneRow(cell))+"  "); 
            System.out.print("列簇: " + new String(CellUtil.cloneFamily(cell))+"  "); 
            System.out.print(" 列: " + new String(CellUtil.cloneQualifier(cell))+"  "); 
            System.out.print(" 值: " + new String(CellUtil.cloneValue(cell))+"  "); 
            System.out.println("时间戳: " + cell.getTimestamp()); } }

    //向已经创建好的表添加的列族或列
    public static void insertRow(String tableName, String rowKey, String colFamily, String col, String val) throws IOException 
    { 
        
        Table table = connection.getTable(TableName.valueOf(tableName)); 
        Put put = new Put(rowKey.getBytes()); 
        put.addColumn(colFamily.getBytes(), col.getBytes(), val.getBytes()); 
        table.put(put); 
        table.close(); 
        
    } 
    
    //向已经创建好的表删除指定的列族或列
    public static void deleteRow(String tableName, String rowKey, String colFamily, String col) throws IOException 
    { 
        
        Table table = connection.getTable(TableName.valueOf(tableName)); 
        Delete delete = new Delete(rowKey.getBytes()); 
        delete.addFamily(Bytes.toBytes(colFamily));
        delete.addColumn(Bytes.toBytes(colFamily), Bytes.toBytes(col)); 
        table.delete(delete); 
        table.close();
        
    }
    //清空指定的表的所有记录数据
    public static void clearRows(String tableName) throws IOException 
    { 
        
        TableName tablename = TableName.valueOf(tableName); 
        admin.disableTable(tablename); 
        admin.truncateTable(tablename, false); 
        
    }
    //统计表的行数
    public static void countTable(String tableName) throws IOException 
    { 
        
        Table table = connection.getTable(TableName.valueOf(tableName)); 
        Scan scan = new Scan(); 
        ResultScanner scanner = table.getScanner(scan); 
        int num = 0; 
        for (Result result = scanner.next(); result != null; result = scanner .next()) 
        { 
            num++; 
        } 
        System.out.println("行数:" + num); 
        scanner.close(); 
    }


    //初始化
        public static void init() 
        { 
            configuration = HBaseConfiguration.create();
            configuration.set("hbase.rootdir", "hdfs://localhost:9000/hbase"); 
            try
            { 
                connection = ConnectionFactory.createConnection(configuration); 
                admin = connection.getAdmin(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace();    
            } 
            
        } 
    //关闭hbase
    public static void close() 
    { 
        try 
        { 
            if (admin != null) 
            { 
                admin.close();     
            } 
            if (connection != null) 
            { 
                connection.close();     
            } 
        } 
        catch (IOException e) 
        { 
            e.printStackTrace(); 
        } 
        
    } 
    //主函数
    public static void main(String[] args) 
    {  
        try 
        {  
            int n=0;
            init(); 
            Scanner in = new Scanner(System.in);
            while(n!=7)
            {
                System.out.println("1.列出 Hbase 所有的表的信息");
                System.out.println("2.在终端打印出指定表的所有记录数据");
                System.out.println("3.向已创建好的表添加指定的列族列");
                System.out.println("4.向已创建好的表删除指定的列族列");
                System.out.println("5.清空指定的表的所有记录数据");
                System.out.println("6.统计表的行数");
                System.out.println("7.退出");
                System.out.println("请选择：");
                if(in.hasNextInt())
                {
                    n=in.nextInt();
                }
                else
                {
                    System.out.println("输入的不是整数，请重新输入：");
                    continue;
                }
                switch(n)
                {
                case 1:listTables(); break;
                case 2:getData("student");break;
                case 3:insertRow("student", "00000000", "score", "math", "99"); break;
                case 4:deleteRow("student", "00000000", "score", "math");  break;
                case 5:clearRows("student"); break;
                case 6:countTable("student"); break;
                case 7:break;
                default:System.out.println("输入错误，请重新输入");
                }
            }
            close();
        } 
        catch (IOException e)
        { 
            e.printStackTrace(); 
        } 
    }
    
}