Hbase的API操作

Hbase的API操作

一、解压Maven离线仓库到指定的目录

我这次使用的是linux环境下的eclipse来进行操作的，所以我们先配置linux的maven仓库，当然你也可以在window环境下进行操作然后打成jar包在linux下进行执行。

$ tar -zxf /opt/softwares/hbase+hadoop_repository.tar.gz -C ~/.m2/

二、编写相应的代码

使用api进行hbase的创建表、删除表、增加一行数据、增加多行数据、查询所有数据操作。

package com.z.hbase;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

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.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.Delete;
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;
import org.apache.hadoop.hdfs.server.namenode.decommission_jsp;



public class HBaseDemo {
    //创建Hadoop以及HBased管理配置对象
    public static Configuration conf;
    
    static{
        //使用HBaseConfiguration的单例方法实例化
        conf = HBaseConfiguration.create();
    }
    
    /**
     * 判断表是否已存在
     * @param args
     * @throws IOException 
     * @throws ZooKeeperConnectionException 
     * @throws MasterNotRunningException 
     */
    public static boolean isTableExist(String tableName) throws MasterNotRunningException, ZooKeeperConnectionException, IOException{
        //在HBase中管理、访问表需要先创建HBaseAdmin对象
        HBaseAdmin admin = new HBaseAdmin(conf);
        return admin.tableExists(tableName);
    }
    
    /**
     * 创建表
     * @param args
     * @throws IOException 
     * @throws ZooKeeperConnectionException 
     * @throws MasterNotRunningException 
     */
    public static void createTable(String tableName, String... columnFamily) throws MasterNotRunningException, ZooKeeperConnectionException, IOException{
        HBaseAdmin admin = new HBaseAdmin(conf);
        //判断表是否存在
        if(isTableExist(tableName)){
            System.out.println("表" + tableName + "已存在");
            //System.exit(0);
        }else{
            //创建表属性对象,表名需要转字节
            HTableDescriptor descriptor = new HTableDescriptor(TableName.valueOf(tableName));
            
            //创建多个列族
            for(String cf : columnFamily){
                descriptor.addFamily(new HColumnDescriptor(cf));
            }
            
            //根据对表的配置，创建表
            admin.createTable(descriptor);
            System.out.println("表" + tableName + "创建成功！");
        }
    }
    
    /**
     * 删除表
     * @param args
     * @throws IOException 
     * @throws ZooKeeperConnectionException 
     * @throws MasterNotRunningException 
     */
    public static void dropTable(String tableName) throws MasterNotRunningException, ZooKeeperConnectionException, IOException{
        HBaseAdmin admin = new HBaseAdmin(conf);
        if(isTableExist(tableName)){
            admin.disableTable(tableName);
            admin.deleteTable(tableName);
            System.out.println("表" + tableName + "删除成功！");
        }else{
            System.out.println("表" + tableName + "不存在！");
        }
        
    }
    
    /**
     * 向表中插入数据
     * @param tableName
     * @param rowKey
     * @param columnFamily
     * @param column
     * @param value
     * @throws IOException 
     */
    public static void addRowData(String tableName, String rowKey, String columnFamily, String column, String value) throws IOException{
        //创建HTable对象
        HTable hTable = new HTable(conf, tableName);
        //向表中插入数据
        Put put = new Put(Bytes.toBytes(rowKey));
        //向Put对象中组装数据
        put.add(Bytes.toBytes(columnFamily), Bytes.toBytes(column), Bytes.toBytes(value));
        hTable.put(put);
        hTable.close();
        System.out.println("插入数据成功");
    }
    
    /**
     * 删除多行数据
     * @param tableName
     * @param rows
     * @throws IOException 
     */
    public static void deleteMultiRow(String tableName, String... rows) throws IOException{
        HTable hTable = new HTable(conf, tableName);
        List<Delete> deleteList = new ArrayList<Delete>();
        for(String row : rows){
            Delete delete = new Delete(Bytes.toBytes(row));
            deleteList.add(delete);
        }
        hTable.delete(deleteList);
        hTable.close();
    }
    
    /**
     * 得到所有的数据
     * @param tableName
     * @throws IOException 
     */
    public static void getAllRows(String tableName) throws IOException{
        HTable hTable = new HTable(conf, tableName);
        //得到用于扫描region的对象
        Scan scan = new Scan();
        //使用HTable得到resultcanner实现类的对象
        ResultScanner resultScanner = hTable.getScanner(scan);
        for(Result result : resultScanner){
            Cell[] cells = result.rawCells();
            for(Cell cell : cells){
                //得到rowkey
                System.out.println(Bytes.toString(CellUtil.cloneRow(cell)));
                //得到列族
                System.out.println(Bytes.toString(CellUtil.cloneFamily(cell)));
                System.out.println(Bytes.toString(CellUtil.cloneQualifier(cell)));
                System.out.println(Bytes.toString(CellUtil.cloneValue(cell)));
            }
        }
        
    }
    
    public static void main(String[] args) {
            try {
//                System.out.println(isTableExist("student"));
//                createTable("person", "basic_info", "job", "heathy");
//                dropTable("person");
//                addRowData("person", "1001", "basic_info", "name", "Nick");
//                addRowData("person", "1001", "basic_info", "sex", "Male");
//                addRowData("person", "1001", "basic_info", "age", "18");
//                addRowData("person", "1001", "job", "dept_no", "7981");
                
//                deleteMultiRow("person", "person");
                getAllRows("person");
                
                
            } catch (Exception e) {
                e.printStackTrace();
            }
    }

}