hbase使用MapReduce操作4（实现将 HDFS 中的数据写入到 HBase 表中）

实现将 HDFS 中的数据写入到 HBase 表中

Runner类

package com.yjsj.hbase_mr2;

import com.yjsj.hbase_mr2.ReadFruitFromHDFSMapper;
import com.yjsj.hbase_mr2.WriteFruitMRFromTxtReducer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
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;

import java.io.IOException;

class Txt2FruitRunner extends Configured implements Tool {
    public int run(String[] args) throws Exception {
//得到 Configuration
        Configuration conf = this.getConf();
//创建 Job 任务
        Job job = Job.getInstance(conf, this.getClass().getSimpleName());
        job.setJarByClass(Txt2FruitRunner.class);
        Path inPath = new Path("hdfs://master:9000/input_fruit/fruit.tsv");

        FileInputFormat.addInputPath(job, inPath);
        //设置 Mapper
        job.setMapperClass(ReadFruitFromHDFSMapper.class);
        job.setMapOutputKeyClass(ImmutableBytesWritable.class);
        job.setMapOutputValueClass(Put.class);
        //设置 Reducer
        TableMapReduceUtil.initTableReducerJob("fruit_hdfs", WriteFruitMRFromTxtReducer.class, job);
        //设置 Reduce 数量，最少 1 个
        job.setNumReduceTasks(1);
        boolean isSuccess = job.waitForCompletion(true);
        if (!isSuccess) {
            throw new IOException("Job running with error");
        }
        return isSuccess ? 0 : 1;
    }

    public static void main(String[] args) throws Exception {
        Configuration conf = HBaseConfiguration.create();
        conf = HBaseConfiguration.create();
        conf.set("hbase.zookeeper.quorum", "master,node1,node2");
        conf.set("hbase.zookeeper.property.clientPort", "2181");
        conf.set("hbase.master", "master:60000");
        int status = ToolRunner.run(conf, new Txt2FruitRunner(), args);
        System.exit(status);
    }
}

Mapper类

package com.yjsj.hbase_mr2;

import java.io.IOException;

import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;

public class ReadFruitFromHDFSMapper extends Mapper<LongWritable, Text, ImmutableBytesWritable, Put> {
    @Override
    protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        //从 HDFS 中读取的数据
        String lineValue = value.toString();
        //读取出来的每行数据使用	 进行分割，存于 String 数组
        String[] values = lineValue.split("	");
        //根据数据中值的含义取值
        String rowKey = values[0];
        String name = values[1];
        String color = values[2];
        //初始化 rowKey
        ImmutableBytesWritable rowKeyWritable = new ImmutableBytesWritable(Bytes.toBytes(rowKey));
        //初始化 put 对象
        Put put = new Put(Bytes.toBytes(rowKey));
        //参数分别:列族、列、值
        put.add(Bytes.toBytes("info"), Bytes.toBytes("name"), Bytes.toBytes(name));
        put.add(Bytes.toBytes("info"), Bytes.toBytes("color"), Bytes.toBytes(color));
        context.write(rowKeyWritable, put);
    }
}

Reduce类

package com.yjsj.hbase_mr2;

import java.io.IOException;

import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableReducer;
import org.apache.hadoop.io.NullWritable;

public class WriteFruitMRFromTxtReducer extends TableReducer<ImmutableBytesWritable, Put, NullWritable> {
    @Override
    protected void reduce(ImmutableBytesWritable key, Iterable<Put> values, Context context) throws IOException, InterruptedException {
        //读出来的每一行数据写入到 fruit_hdfs 表中
        for (Put put : values) {
            context.write(NullWritable.get(), put);
        }
    }
}