如何进行流量统计二

再继承Reducer，并重写reduce函数

package org.example.flow; 
  import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Reducer;  
 import java.io.IOException;  
 //1继承Reducer //2重写reduce函数 public class FlowReducer extends Reducer<Text,FlowBean,Text,Text> {     @Override   
  protected void reduce(Text key, Iterable<FlowBean> values, Context context) throws IOException, InterruptedException {       
  //1遍历集合，取出每一个元素，计算上行流量和下行流量的总汇        
 long upFlowSum = 0L;       
  long downFlowSum = 0L;   
      for (FlowBean flowBean : values) {        
     upFlowSum += flowBean.getUpFlow();   
          downFlowSum += flowBean.getDownFlow();         }      
   //2计算总的汇总      
   long sumFlow = upFlowSum + downFlowSum;      
   String flowDesc =String.format("总的上行流量是:%d 总的下行流量:%d 总流量是:%d",upFlowSum,downFlowSum,sumFlow);    
     context.write(key, new Text(flowDesc));     } }

再去提交job和进行关联mapper和reducer进行汇总设置输出类型路径

package org.example.flow;   
import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; 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.IOException;    
 //提交job的类，一共做7件事 public class FlowDriver { 
public static void main(String[] args) throws IOException, InterruptedException, ClassNotFoundException {   
  //1获取配置，得到job对象   
  Configuration conf=new Configuration();   
  Job job= Job.getInstance(conf);  
   //2设置job包路径    
 job.setJarByClass(FlowDriver.class);   
  //3关联Mapper和Reducer   
  job.setMapperClass(FlowMapper.class);   
  job.setReducerClass(FlowReducer.class);   

  //4设置Mapper输出类型    
 job.setMapOutputKeyClass(Text.class);  
   job.setMapOutputValueClass(FlowBean.class);  
   //5设置reducer输出类型 

    job.setOutputKeyClass(Text.class);   
  job.setOutputValueClass(Text.class);  
   //6设置输入和输出路径    
 FileInputFormat.setInputPaths(job,new Path("data"));   
  FileOutputFormat.setOutputPath(job,new Path("output"));// 

    //7提交job根据返回值设置程序退出code   
  boolean result=job.waitForCompletion(true);   
  System.exit(result?0:1);
 } 
}

进行运行生成一个output目录 part-r-00000中则会生成结果