HBase笔记 -- API Demo

import java.io.IOException;

import java.io.ByteArrayOutputStream;

import java.io.DataOutputStream;

import java.io.ByteArrayInputStream;

import java.io.DataInputStream;

import java.util.Map;

import org.apache.hadoop.io.Writable;

import org.apache.hadoop.io.IntWritable;

import org.apache.hadoop.hbase.HBaseConfiguration;

import org.apache.hadoop.hbase.HTableDescriptor;

import org.apache.hadoop.hbase.HColumnDescriptor;

import org.apache.hadoop.hbase.client.HBaseAdmin;

import org.apache.hadoop.hbase.client.HTable;

import org.apache.hadoop.hbase.io.BatchUpdate;

import org.apache.hadoop.hbase.io.RowResult;

import org.apache.hadoop.hbase.io.Cell;

import org.apache.hadoop.hbase.util.Writables;



public class HBaseBasic {



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

        HBaseConfiguration config = new HBaseConfiguration();

        HBaseAdmin admin = new HBaseAdmin(config);



        if (admin.tableExists("scores")) {

            System.out.println("drop table");

            admin.disable Table("scores");

            admin.deleteTable("scores");

        }



        System.out.println("create table");

        HTableDescriptor tableDescripter = new HTableDescriptor("scores".getBytes());

        tableDescripter.addFamily(new HColumnDescriptor("grade:"));

        tableDescripter.addFamily(new HColumnDescriptor("course:"));

        admin.createTable(tableDescripter);



        HTable table = new HTable(config, "scores");



        System.out.println("add Tom's data ");

        BatchUpdate tomUpdate = new BatchUpdate("Tom");

        tomUpdate.put("grade:", Writables.getBytes(new IntWritable(1)));

        tomUpdate.put("course:math", Writables.getBytes(new IntWritable(87)));

        tomUpdate.put("course:art", Writables.getBytes(new IntWritable(97)));

        table.commit(tomUpdate);



        System.out.println("add Jerry's data");

        BatchUpdate jerryUpdate = new BatchUpdate("Jerry");

        jerryUpdate.put("grade:", Writables.getBytes(new IntWritable(2)));

        jerryUpdate.put("course:math", Writables.getBytes(new IntWritable(100)));

        jerryUpdate.put("course:art", Writables.getBytes(new IntWritable(80)));

        table.commit(jerryUpdate);


        for (RowResult row : table.getScanner(new String[] { "course:" })) {

            System.out.format("ROW\t%s\n", new String(row.getRow()));

            for (Map.Entry<byte[], Cell> entry : row.entrySet()) {

                String column = new String(entry.getKey());

                Cell cell = entry.getValue();

                IntWritable value = new IntWritable();

                Writables.copyWritable(cell.getValue(), value);

                System.out.format("  COLUMN\t%s\t%d\n", column, value.get());

            }

        }

    }

}

输出如下:

drop table

09/07/11 08:51:59 INFO client.HBaseAdmin: Disabled scores

09/07/11 08:51:59 INFO client.HBaseAdmin: Deleted scores

create table

add Tom's data

add Jerry's data

ROW     Tom

  COLUMN        course:art      97

  COLUMN        course:math     87

ROW     Jerry

  COLUMN        course:art      80

  COLUMN        course:math     100