HBase_API_（HBaseDML，对数据的api）

package com.atguigu;

import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;

import java.io.IOException;

public class HBaseDML {

    //添加静态属性
    public static Connection connection = HBaseConnection.connection;

    /**
     * 插入数据
     * @param namespace 命名空间名称
     * @param tableName 表格名称
     * @param rowKey    主键
     * @param columnFamily  列族
     * @param columnName    列名
     * @param value         值
     */
    public static void putCell(String namespace, String tableName, String rowKey, String columnFamily, String columnName, String value) throws IOException {
        //1.获取table(对数据进行操作要获取table，对表格进行操作要获取admin)
        Table table = connection.getTable(TableName.valueOf(namespace, tableName));

        //2.调用方法插入数据
        Put put = new Put(Bytes.toBytes(rowKey));

        //3.给put对象添加数据
        put.addColumn(Bytes.toBytes(columnFamily),Bytes.toBytes(columnName),Bytes.toBytes(value));

        //4.将对象写入对应方法
        try {
            table.put(put);
        } catch (IOException e) {
//            throw new RuntimeException(e);
            e.printStackTrace();
        }

        //关闭table
        table.close();

    }


    /**
     * 读取数据  读取对应的某一列
     * @param namespace 命名空间
     * @param tableName 表格名称
     * @param rowKey    主键
     * @param columnFamily  列族
     * @param columnName    列名
     */
    public static void getCells(String namespace,String tableName,String rowKey,String columnFamily,String columnName) throws IOException {
        //1.获取table对象
        Table table = connection.getTable(TableName.valueOf(namespace,tableName));

        //2.创建get对象
        Get get = new Get(Bytes.toBytes(rowKey));

        //读取某一列的数据:添加属性
        get.addColumn(Bytes.toBytes(columnFamily),Bytes.toBytes(columnName));

        //也可以设置读取版本
        get.readAllVersions();

        try {

            //获取读取对象
            Result result = null;
            result = table.get(get);


            //处理数据
            Cell[] cells = result.rawCells();

            //
            for (Cell cell : cells) {
                //cell
                String value = new String(CellUtil.cloneValue(cell));
                System.out.println(value);

            }
        } catch (IOException e) {
//            throw new RuntimeException(e);
            e.printStackTrace();
        }


        //关闭table
        table.close();

    }


    /**
     * 扫描数据
     * @param namespace 命名空间
     * @param tableName 表格名称
     * @param startRow  开始row   包含的
     * @param stopRow   暂停row   不包含
     */
    public static void scanRows(String namespace,String tableName, String startRow, String stopRow) throws IOException {

        //1.获取table
        Table table = connection.getTable(TableName.valueOf(namespace, tableName));

        //调用对应方法
        Scan scan = new Scan();

        //添加参数控制扫描数据
        scan.withStartRow(Bytes.toBytes(startRow)); //包含
        scan.withStopRow(Bytes.toBytes(stopRow));   //不包含

        try {
            //读取数据，获得scanner对象
            ResultScanner scanner = null;
            scanner = table.getScanner(scan);

            //result记录一行数据，cell数据
            //Resultscanner记录多行数据，result数组
            for (Result result : scanner) {

                Cell[] cells = result.rawCells();

                for (Cell cell : cells) {
                    System.out.print(new String(CellUtil.cloneRow(cell))+"-"+
                            new String(CellUtil.cloneFamily(cell))+"-"+
                            new String(CellUtil.cloneQualifier(cell))+"-"+
                            new String(CellUtil.cloneValue(cell))+"\t");
                }

                System.out.println();

            }


        } catch (IOException e) {
//            throw new RuntimeException(e);
            e.printStackTrace();

        }


        //关闭table
        table.close();

    }



    public static void main(String[] args) throws IOException {

        //1.添加数据测试
//        putCell("atguigu","student","01","msg","stuname","*****");


        //2.测试读取数据
//        getCells("atguigu","student","01","msg","stuname");


        //3.测试扫描数据
        scanRows("atguigu","student","01","03");

        System.out.println("------------------------------");

        //记得关闭hbase连接
        HBaseConnection.closeConnection();

    }
}