10月30日課堂測試

時間 2019-11-11
標籤 10月 30日課堂測試简体版
原文原文鏈接
 
         package 
         mapreduce; 
        
         import 
         java.io.IOException; 
        
         import 
         java.util.StringTokenizer; 
        
         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.Mapper; 
        
         import 
         org.apache.hadoop.mapreduce.Reducer; 
        
         import 
         org.apache.hadoop.mapreduce.lib.input.FileInputFormat; 
        
         import 
         org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; 
        
         public 
         class 
         WordCount1{ 
        
         public 
         static 
         void 
         main(String[] args)  
         throws 
         IOException,ClassNotFoundException,InterruptedException { 
        
         Job job = Job.getInstance(); 
        
         job.setJobName( 
         "WordCount1" 
         ); 
        
         job.setJarByClass(WordCount1. 
         class 
         ); 
        
         job.setMapperClass(doMapper. 
         class 
         ); 
        
         job.setReducerClass(doReducer. 
         class 
         ); 
        
         job.setOutputKeyClass(Text. 
         class 
         ); 
        
         job.setOutputValueClass(IntWritable. 
         class 
         ); 
        
         Path in =  
         new 
         Path( 
         "hdfs://localhost:9000/mymapreduce1/in/buyer_favorite1" 
         ); 
        
         Path out =  
         new 
         Path( 
         "hdfs://localhost:9000/mymapreduce1/out" 
         ); 
        
         FileInputFormat.addInputPath(job,in); 
        
         FileOutputFormat.setOutputPath(job,out); 
        
         System.exit(job.waitForCompletion( 
         true 
         )? 
         0 
         : 
         1 
         ); 
        
         } 
        
         public 
         static 
         class 
         doMapper  
         extends 
         Mapper<Object,Text,Text,IntWritable>{ 
        
         public 
         static 
         final 
         IntWritable one =  
         new 
         IntWritable( 
         1 
         ); 
        
         public 
         static 
         Text word =  
         new 
         Text(); 
        
         @Override 
        
         protected 
         void 
         map(Object key, Text value, Context context) 
        
         throws 
         IOException,InterruptedException { 
        
         StringTokenizer tokenizer =  
         new 
         StringTokenizer(value.toString(), 
         "  " 
         ); 
        
         word.set(tokenizer.nextToken()); 
        
         context.write(word,one); 
        
         } 
        
         } 
        
         public 
         static 
         class 
         doReducer  
         extends 
         Reducer<Text,IntWritable,Text,IntWritable>{ 
        
         private 
         IntWritable result =  
         new 
         IntWritable(); 
        
         @Override 
        
         protected 
         void 
         reduce(Text key,Iterable<IntWritable> values,Context context) 
        
         throws 
         IOException,InterruptedException{ 
        
         int 
         sum =  
         0 
         ; 
        
         for 
         (IntWritable value : values){ 
        
         sum += value.get(); 
        
         } 
        
         result.set(sum); 
        
         context.write(key,result); 
        
         } 
        
         } 
        
         }