一、分析数据处理的过程
二、程序代码
2.1 main程序
@H_404_11@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;
public class SalaryTotalMain {
public static void main(String[] args) throws Exception {
//1、创建任务Job，并且指定任务的入口
Job job = Job.getInstance(new Configuration());
job.setJarByClass(SalaryTotalMain.class);
//2、指定任务的Map，Map的输出类型
job.setMapperClass(SalaryTotalMapper.class);
job.setMapOutputKeyClass(IntWritable.class); //k2
job.setMapOutputValueClass(IntWritable.class); //v2
//3、指定任务的Reduce，Reduce的输出类型
job.setReducerClass(SalaryTotalReducer.class);
job.setoutputKeyClass(IntWritable.class); //k4
job.setoutputValueClass(IntWritable.class); //v4
//4、指定任务的输入路径和输出路径
FileInputFormat.setInputPaths(job, new Path(args[0]));
FileOutputFormat.setoutputPath(job, new Path(args[1]));
//5、执行任务
job.waitForCompletion(true);
}
}
2.2 Map程序
@H_404_11@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 SalaryTotalMapper extends Mapper<LongWritable, Text,IntWritable, IntWritable> {
@Override
protected void map(LongWritable key1, Text value1, Context context) throws IOException, InterruptedException {
/*
context代表Map的上下文
上文：DHFS的输入
下文：Reduce
*/
String data =value1.toString();
String [] words = data.split(",");
for ( String w:words){
context.write(new IntWritable(Integer.parseInt(words[7])),new IntWritable(Integer.parseInt(words[5])));
}
}
}
2.1 Reduce程序
@H_404_11@import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapreduce.Reducer;
import java.io.IOException;
public class SalaryTotalReducer extends Reducer<IntWritable, IntWritable,IntWritable,IntWritable> {
@Override
protected void reduce(IntWritable k3, Iterable<IntWritable> v3, Context context) throws IOException, InterruptedException {
int total = 0;
for (IntWritable v:v3){
total += v.get();
}
context.write(k3,new IntWritable(total));
}
}
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