目录

1.前情回顾

2.需求

3.编码

3.1 新建 Maven 项目 YarnDemo

3.2 新建 com.xxxx.yarn包名

3.3 创建类 WordCount 并实现 Tool 接口

3.3 新建WordCountDriver类

1.前情回顾

[atguigu@hadoop102 hadoop-3.1.3]$ hadoop jar wc.jar 
com.atguigu.mapreduce.wordcount2.WordCountDriver /input /output1

期望可以动态传参，结果报错，误认为是第一个输入参数。

[atguigu@hadoop102 hadoop-3.1.3]$ hadoop jar wc.jar 
com.atguigu.mapreduce.wordcount2.WordCountDriver -Dmapreduce.job.queuename=root.test /input /output1

2.需求

自己写的程序也可以动态修改参数。编写 Yarn 的 Tool 接口

3.编码

3.1 新建 Maven 项目 YarnDemo

 4.0.0
 com.atguigu.hadoop
 yarn_tool_test
 1.0-SNAPSHOT
 
 
 org.apache.hadoop
 hadoop-client
 3.1.3
 
 

3.2 新建 com.xxxx.yarn包名

3.3 创建类 WordCount 并实现 Tool 接口

package com.yangmin.yarn;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;

;import java.io.IOException;

public class WordCount implements Tool {
    private Configuration conf;

    public int run(String[] args) throws Exception {
        Job job = Job.getInstance(conf);

        job.setJarByClass(WordCountDriver.class);
        job.setMapperClass(WordCountMapper.class);
        job.setReducerClass(WordCountReducer.class);

        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(IntWritable.class);

        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);

        FileInputFormat.setInputPaths(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));

        return job.waitForCompletion(true) ? 0 : 1;
    }

    public void setConf(Configuration configuration) {
        this.conf = configuration;
    }

    public Configuration getConf() {
        return conf;
    }

    //map函数
    public static class WordCountMapper extends Mapper {
        private Text outK = new Text();
        private IntWritable outV = new IntWritable(1);

        @Override
        protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
            String line = value.toString();
            String[] words = line.split(" ");
            for (String word : words) {
                outK.set(word);
                context.write(outK, outV);
            }
        }
    }

    public static class WordCountReducer extends Reducer {
        private IntWritable outV = new IntWritable();

        @Override
        protected void reduce(Text key, Iterable values, Context context) throws IOException, InterruptedException {
            int sum = 0;
            for (IntWritable value : values) {
                sum += value.get();
            }
            outV.set(sum);
            context.write(key, outV);
        }
    }
}

3.3 新建WordCountDriver类

package com.yangmin.yarn;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

import java.util.Arrays;

public class WordCountDriver {
    private static Tool tool;

    public static void main(String[] args) throws Exception {
        //创建配置
        Configuration conf = new Configuration();

        switch (args[0]){
            case "wordcount":
                tool = new WordCount();
                break;
            default:
                throw new RuntimeException("no such tool" + args[0]);
        }

        //执行炒程序
        int run = ToolRunner.run(conf, tool, Arrays.copyOfRange(args, 1, args.length));
        System.exit(run);
    }
}