学习笔记:从0开始学习大数据-7.hbase java编程hello world

上节搭建了hbase启动环境，本节搭建hbase编程环境

1. 准备测试数据，创建表student

#hbase shell

create 'student','info','address'
put 'student','1','info:age','20'
put 'student','1','info:name','linbin'
put 'student','1','info:class','1'
put 'student','1','address:city','guangzhou'
put 'student','1','address:area','baiyun zone'
put 'student','2','info:age','21'
put 'student','2','info:name','yangdandan'
put 'student','2','info:class','1'
put 'student','2','address:city','beijing'
put 'student','2','address:area','CBD'
scan 'student'

2. Eclipse 创建hbase项目

文件-》新建-》项目-》maven project->输入项目名-》完成

3.修改项目下的pom.xml  增加

    <dependency>
        <groupId>org.apache.hbase</groupId>
        <artifactId>hbase-it</artifactId>
        <version>1.2.0</version>
    </dependency>

保存后等待自动下载相关jar文件

4. 修改 App.java 文件

package com.linbin.hbase;

import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.util.Bytes;

public class App 
{
	private static Configuration config = null;
	private static Connection connection = null;
	private static Table table = null;
    public static void main( String[] args ) throws Exception
    {
		config = HBaseConfiguration.create();
		config.set("hbase.zookeeper.quorum", "centos7");    //指定服务器
		connection = ConnectionFactory.createConnection(config);
		table = connection.getTable(TableName.valueOf("student"));  //打开student表
		queryData();
		table.close();
		connection.close();
    }
    
	public static void queryData() throws IOException {
		Get get = new Get(Bytes.toBytes("2"));    //获取表的行key
		Result result = table.get(get);
		System.out.println(Bytes.toString(result.getValue(Bytes.toBytes("info"), Bytes.toBytes("name"))));   //输出 info：name列
		System.out.println(Bytes.toString(result.getValue(Bytes.toBytes("info"), Bytes.toBytes("age"))));    //输出  info:age列
	}
}

简单的连接hbase数据库，打开表，查询指定行，打印指定列，关闭表和连接。

5. 测试运行，注意运行时 Run as -> Java application    这个不是web项目，是java应用程序项目

正常执行，显示查询的结果

6. 编程实现hbase表的增删改查java api 参见：

https://blog.youkuaiyun.com/u014695188/article/details/73188668   hbase编程：通过Java api操作hbase