[游戏开发]HBase API 与MR交互：将 fruit 表中的数据，通过 MR 迁入到 fruit1表中

1.构建ReadFruitMapper类，用于读取 fruit 表中的数据

package test;

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

import java.io.IOException;

//读取HBase中的表数据，写入Reducer
public class ReadFruitMapper extends Mapper <LongWritable, Text,LongWritable, Text>{

    @Override
    protected void map(LongWritable key, Text value, Mapper<LongWritable, Text, LongWritable, Text>.Context context) throws IOException, InterruptedException {

        context.write(key,value);

    }

}

2.构建WriteFruitMRReducer类，用于将读取到的 fruit 表中的数据写入到 fruit1?表中、

package test;

import org.apache.hadoop.hbase.client.Mutation;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.mapreduce.TableReducer;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;

import java.io.IOException;

//将Reducer中的数据写入HBase的表中
public class WriteFruitMRReducer extends TableReducer<LongWritable, Text, NullWritable> {

    @Override
    protected void reduce(LongWritable key, Iterable<Text> values, Reducer<LongWritable, Text, NullWritable, Mutation>.Context context) throws IOException, InterruptedException {

        //1.遍历values
        for (Text value : values) {
            //1.1获取每行数据
            String[] fields = value.toString().split("\t");

            //1.2构建put对象
            Put put = new Put(Bytes.toBytes(fields[0]));

            //1.3给put对象赋值
            put.addColumn(Bytes.toBytes("info"),Bytes.toBytes("name"),Bytes.toBytes(fields[1]));
            put.addColumn(Bytes.toBytes("info"),Bytes.toBytes("color"),Bytes.toBytes(fields[2]));

            //1.4写出数据
            context.write(NullWritable.get(),put);
        }

    }
}

3.构建FruitMRDriver类，用于提交运行任务

package test;

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 FruitMRDriver implements Tool {

    //定义一个Configuration
    private Configuration configuration = null;

    @Override
    public int run(String[] args) throws Exception {

        //1.获取Job对象
        Job job = Job.getInstance(configuration);
        //2.设置驱动类路径
        job.setJarByClass(FruitMRDriver.class);
        //3.设置Mapper&Mapper输出的KV类型
        job.setMapperClass(ReadFruitMapper.class);
        job.setMapOutputKeyClass(LongWritable.class);
        job.setMapOutputValueClass(Text.class);
        //4.设置Reducer类
        TableMapReduceUtil.initTableReducerJob(args[1],WriteFruitMRReducer.class,job);
        //5.设置最终的输出数据的KV类型
        //6.设置输入参数
        FileInputFormat.setInputPaths(job,new Path(args[0]));
        //6.提交任务
        boolean result = job.waitForCompletion(true);

        return result?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 FruitMRDriver(), args);

            System.exit(run);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

4.将FruitMRDriver类打成jar包，上传至HBase。

5.新建一个表（fruit1）

6.利用jar包运行任务

yarn jar jar/hbase01-1.0-SNAPSHOT.jar test.FruitMRDriver /hbase/hbasetest/bigdatafile/input/fruit.tsv fruit1

7.运行成功后，查看fruit1表中的数据是否传入成功！！！

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