关于java:环境大数据MapReduce

mapper
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 MavgaqiMapper extends Mapper<LongWritable, Text,Text,IntWritable> {

@Overrideprotected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {    //疏忽首行    //用key判断，第一行的key肯定是0    if (key.get()==0) {        return;    }    //字符串类型转成java类型    String data = value.toString();    //切片成数组，一共有9个元素    String[] msgs = data.split(",");    if (!(msgs[6].equals("N/A"))){        context.write(new Text(msgs[0]),new IntWritable(Integer.parseInt(msgs[6])));    }}

}
reducer
import org.apache.hadoop.io.FloatWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;
import java.io.IOException;
public class MavgaqiReducer extends Reducer<Text, IntWritable,Text, IntWritable> {

@Overrideprotected void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {    //把解决的每一个201601的value值都加起来    int total = 0;    int count = 0;    int avg = 0;    for (IntWritable v:values){        //把IntWritable类型转化为int型        count++;        total += v.get();    }    avg = total/count;    //total由int类型变为FloatWritable类型    context.write(key,new IntWritable(avg));}

}
main
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.FloatWritable;
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;
public class MavgaqiMain {

public static void main(String[] args) throws Exception {    Job job = Job.getInstance(new Configuration());    //程序主类    job.setJarByClass(MavgaqiMain.class);    //Mapper类的相干设置    job.setMapperClass(MavgaqiMapper.class);    //Map输入key，[PerfectMoney下载](https://www.gendan5.com/wallet/PerfectMoney.html)value类型    job.setMapOutputKeyClass(Text.class);    job.setMapOutputValueClass(IntWritable.class);    //Reducer类的相干设置    job.setReducerClass(MavgaqiReducer.class);    //程序运行输入key,value类型    job.setOutputKeyClass(Text.class);    job.setOutputValueClass(IntWritable.class);    //设置输出，输入门路    FileInputFormat.setInputPaths(job,new Path(args[0]));    FileOutputFormat.setOutputPath(job,new Path(args[1]));    //提交工作，并期待工作运行实现    job.waitForCompletion(true);}

}