北京2019年空气质量等级数据分析与可视化

import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import java.io.IOException;
public class Air16Mapper extends Mapper {
@Override
protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
//super.map(key, value, context);
String line=value.toString(); //[2019-01-01 良 53 128 35 52]
String[] arr=line.split("\\t");
if (arr.length>1){
String quality=arr[1];
// System.out.println(quality);
context.write(new Text(quality),new IntWritable(1));
}
}
}

import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;
import java.io.IOException;
public class Air16Reducer extends Reducer {
@Override
protected void reduce(Text key, Iterable values, Context context) throws IOException, InterruptedException {
//super.reduce(key, values, context);
int sum=0;
for (IntWritable i:values){
sum+=i.get();
}
context.write(key,new IntWritable(sum));
}
}

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import java.io.FileOutputStream;
import java.io.IOException;
public class Air16Runner {
public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {
Configuration conf=new Configuration();
//创建job
Job job= Job.getInstance(conf,"air");
//设置输入输出路径
FileInputFormat.addInputPath(job,new Path(args[0]));
FileOutputFormat.setOutputPath(job,new Path(args[1]));
//设置运行类
job.setJarByClass(Air16Runner.class);
job.setMapperClass(Air16Mapper.class);
job.setReducerClass(Air16Reducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
System.exit(job.waitForCompletion(true)?0:1);
}
}