Hbase-API增删改查扫描等操作

说明:
这是一个maven工程,需要导入相关配置。

在这里插入图片描述
代码

package com.HbasePractice.hbase;

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

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

/**
 * @author lv
 * @version 1.0, 20:44 2019/4/15
 */
public class HbaseTest {

    //配置信息
    public static Configuration conf;

    //获取配置信息
    static {
        //alt + enter
        conf = HBaseConfiguration.create();
    }

    //1.判断一张表是否存在
    public static boolean isExist(String tableName) throws IOException {
        //对表操作需要用HbaseAdmin
        Connection connection = ConnectionFactory.createConnection(conf);
        //管理表
        HBaseAdmin admin = (HBaseAdmin) connection.getAdmin();

        return admin.tableExists(TableName.valueOf(tableName));
    }
    //2.在hbase集群创建表  create 'user','info','info1'
    // String... 表示可变参数
    public static void createTable(String tableName,String... columnFamilly) throws IOException {
        //对表操作需要用HbaseAdmin
        Connection connection = ConnectionFactory.createConnection(conf);
        //管理表
        HBaseAdmin admin = (HBaseAdmin) connection.getAdmin();

        //1.表如果存在 请输入其它表名
        if(isExist(tableName)){
            System.out.println("表存在,请输入其它表名");
        }else{
            //2.注意:创建表的话 需要创建一个描述器
            HTableDescriptor htd = new HTableDescriptor(TableName.valueOf(tableName));

            //3.创建列族
            for(String cf:columnFamilly){
                htd.addFamily(new HColumnDescriptor(cf));
            }

            //4.创建表
            admin.createTable(htd);
            System.out.println("表已创建成功!");
        }
    }
    // 3:删除hbase中的表
    public static void deleteTable(String tableName) throws IOException {
        //对表操作需要用HbaseAdmin
        Connection connection = ConnectionFactory.createConnection(conf);
        //管理表
        HBaseAdmin admin = (HBaseAdmin) connection.getAdmin();

        //1.如果表存在 删除 否则打印不存在
        //需要先指定表不可用 再删除
        if(isExist(tableName)){
            //2.指定不可用,然后再删除
            admin.disableTable(TableName.valueOf(tableName));
            admin.deleteTable(TableName.valueOf(tableName));
        }else{
            System.out.println("表不存在,请重新输入表名!");
        }
    }

    //4.添加数据put 'user','rowkey',''
    public static void addRow(String tableName,String rowkey,String cf,String column,String value) throws IOException {
        //对表操作需要用HbaseAdmin
        Connection connection = ConnectionFactory.createConnection(conf);
        //拿到表对象
        Table t = connection.getTable(TableName.valueOf(tableName));


        //1.用put方式加入数据
        Put p =  new Put(Bytes.toBytes(rowkey));
        //2.加入数据
        p.addColumn(Bytes.toBytes(cf),Bytes.toBytes(column),Bytes.toBytes(value));
        t.put(p);
    }



    //5.删除表中一行数据
    public static void deleteRow(String tableName,String rowkey,String cf) throws IOException {
        //对表操作需要用HbaseAdmin
        Connection connection = ConnectionFactory.createConnection(conf);
        //拿到表对象
        Table t = connection.getTable(TableName.valueOf(tableName));

        //1.根据rowkey删除数据
        Delete d = new Delete(Bytes.toBytes(rowkey));
        //2.删除
        t.delete(d);
    }

    //6.删除多行数据
    public static void deleteAll(String tableName,String... rowkeys) throws IOException {
        //对表操作需要用HbaseAdmin
        Connection connection = ConnectionFactory.createConnection(conf);
        //拿到表对象
        Table t = connection.getTable(TableName.valueOf(tableName));

        //1.把delete封装到集合
        List<Delete> list = new ArrayList<Delete>();
        //2.遍历
        for(String row:rowkeys){
            Delete d = new Delete(Bytes.toBytes(row));
            list.add(d);
        }
        t.delete(list);
    }
    //7.扫面表数据 scan全表扫描
    public static void scanAll(String tableName) throws IOException {
        //对表操作需要用HbaseAdmin
        Connection connection = ConnectionFactory.createConnection(conf);
        //拿到表对象
        Table t = connection.getTable(TableName.valueOf(tableName));

        //1.实例scan
        Scan s = new Scan();
        //2,拿到Scanner对象
        ResultScanner rs = t.getScanner(s);

        //3.遍历
        for(Result r:rs){
            Cell[] cells = r.rawCells();
            //遍历具体数据
            for(Cell c:cells){
                System.out.println("行键为:" + Bytes.toString(CellUtil.cloneRow(c)));
                System.out.println("列族为:" + Bytes.toString(CellUtil.cloneFamily(c)));
                System.out.println("值为:" + Bytes.toString(CellUtil.cloneValue(c)));
                
            }
        }
    }

    //8.扫描指定的数据
    public static void getRow(String tableName,String rowkey) throws IOException {
        //对表操作需要用HbaseAdmin
        Connection connection = ConnectionFactory.createConnection(conf);
        //拿到表对象
        Table t = connection.getTable(TableName.valueOf(tableName));

        //1.扫描指定数据需要实例Get
        Get g = new Get(Bytes.toBytes(rowkey));
        //2.可加过滤条件
        g.addFamily(Bytes.toBytes("info"));

        Result rs = t.get(g);
        Cell[] cells = rs.rawCells();
        //3.遍历
        //遍历具体数据
        for(Cell c:cells){
            System.out.println("行键为:" + Bytes.toString(CellUtil.cloneRow(c)));
            System.out.println("列族为:" + Bytes.toString(CellUtil.cloneFamily(c)));
            System.out.println("值为:" + Bytes.toString(CellUtil.cloneValue(c)));


        }

    }

    public static void main(String[] args) throws IOException {
//        System.out.println(isExist("emp1"));
//        deleteTable("Hunter");
//        createTable("LeronQ","henshuai","feichangshuai");
//         createTable("LeronQ2","info");
//        deleteTable("LeronQ2");
//                addRow("LeronQ2","101","info","age","18");
//                deleteRow("LeronQ2","101","info");
                   deleteAll("emp","1001","1002r");
    }
}

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转载自blog.csdn.net/yilulvxing/article/details/89326802