HBase深入----官方案例MR

1. 首先配置虚拟机的环境变量
   Driver

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;


public class FruitDriver implements Tool {
    //定义一个Conf
    private Configuration configuration = null;

    @Override
    public int run(String[] args) throws Exception {
        //获取job对象

        Job job = Job.getInstance(configuration);
        //设置驱动类路径
        job.setJarByClass(FruitDriver.class);
        //设置mapper和mapper的输出类型
        job.setMapperClass(FruitMapper.class);
        job.setMapOutputKeyClass(LongWritable.class);
        job.setMapOutputValueClass(Text.class);
        //设置reducer

        TableMapReduceUtil.initTableReducerJob(args[1], FruitReducer.class, job);
        //设置最终的输出数据的KV类型

        //设置输入参数
        FileInputFormat.setInputPaths(job, new Path(args[0]));
        //提交任务
        boolean b = job.waitForCompletion(true);

        return b ? 0 : 1;
    }

    @Override
    public void setConf(Configuration conf) {
        configuration = conf;
    }

    @Override
    public Configuration getConf() {
        return configuration;
    }

    public static void main(String[] args) {

        try {
            Configuration configuration = new Configuration();
            int run = ToolRunner.run(configuration, new FruitDriver(), args);
            System.exit(run);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Mapper

import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;

import java.io.IOException;

public class FruitMapper extends Mapper {
    @Override
    protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        context.write(key,value);
    }
}