javac找不到作业类的符号

6jjcrrmo  于 2021-06-01  发布在  Hadoop
关注(0)|答案(1)|浏览(459)

我的执行文件是:

package hadoop; 

import java.util.*; 

import java.io.IOException; 
import java.io.IOException; 

import org.apache.hadoop.fs.Path; 
import org.apache.hadoop.conf.*; 
import org.apache.hadoop.io.*; 
import org.apache.hadoop.mapred.*; 
import org.apache.hadoop.util.*; 
import javax.lang.model.util.Elements;
public class ProcessUnits 
{ 
   //Mapper class 
   public static class E_EMapper extends MapReduceBase implements 
   Mapper<LongWritable ,/*Input key Type */ 
   Text,                /*Input value Type*/ 
   Text,                /*Output key Type*/ 
   IntWritable>        /*Output value Type*/ 
   { 

      //Map function 
      public void map(LongWritable key, Text value, 
      OutputCollector<Text, IntWritable> output,   
      Reporter reporter) throws IOException 
      { 
         String line = value.toString(); 
         String lasttoken = null; 
         StringTokenizer s = new StringTokenizer(line,"\t"); 
         String year = s.nextToken(); 

         while(s.hasMoreTokens())
            {
               lasttoken=s.nextToken();
            } 

         int avgprice = Integer.parseInt(lasttoken); 
         output.collect(new Text(year), new IntWritable(avgprice)); 
      } 
   } 

   //Reducer class 
   public static class E_EReduce extends MapReduceBase implements 
   Reducer< Text, IntWritable, Text, IntWritable > 
   {  

      //Reduce function 
      public void reduce( Text key, Iterator <IntWritable> values, 
         OutputCollector<Text, IntWritable> output, Reporter reporter) throws IOException 
         { 
            int maxavg=30; 
            int val=Integer.MIN_VALUE; 

            while (values.hasNext()) 
            { 
               if((val=values.next().get())>maxavg) 
               { 
                  output.collect(key, new IntWritable(val)); 
               } 
            } 

         } 
   }  

   //Main function 
   public static void main(String args[])throws Exception 
   { 
      JobConf conf = new JobConf(Eleunits.class); 

      conf.setJobName("max_eletricityunits"); 
      conf.setOutputKeyClass(Text.class);
      conf.setOutputValueClass(IntWritable.class); 
      conf.setMapperClass(E_EMapper.class); 
      conf.setCombinerClass(E_EReduce.class); 
      conf.setReducerClass(E_EReduce.class); 
      conf.setInputFormat(TextInputFormat.class); 
      conf.setOutputFormat(TextOutputFormat.class); 

      FileInputFormat.setInputPaths(conf, new Path(args[0])); 
      FileOutputFormat.setOutputPath(conf, new Path(args[1])); 

      JobClient.runJob(conf); 
   } 
}

当我编译它时:
javac-classpath/home/javier/entrada/hadoop-core-1.2.1.jar-d/home/javier/units/home/javier/entrada/processunits.java
我有以下错误:

javac -classpath /home/javier/entrada/hadoop-core-1.2.1.jar -d /home/javier/units /home/javier/entrada/ProcessUnits.java
/home/javier/entrada/ProcessUnits.java:72: error: cannot find symbol
      JobConf conf = new JobConf(Eleunits.class); 
                                 ^
  symbol:   class Eleunits
  location: class ProcessUnits
1 error

我的hadoop版本是2.9.2,java版本是1.8.0\u191
当我用eclipse打开它并查看它时,我没有找到eleunits.class的导入

x8goxv8g

x8goxv8g1#

我的hadoop版本是2.9.2,java版本是1.8.0\u191
首先, hadoop-core-1.2.1.jar 是在hadoop2.9.2之前构建的,所以你需要一个新的jar
当我用eclipse打开它并查看它时,我没有找到eleunits.class的导入
不清楚你为什么一直不使用eclipse!即使不使用maven或gradle为hadoop获取正确的库版本,对我来说也是可怕的。。。但eclipse可能没有撒谎。您只显示了一个类,而该类没有被调用 Eleunits ,我不知道你是怎么得到这个值的,除了从其他地方复制的
除此之外,主要的班级应该 extends Configured implements Tool ,您将在其他mapreduce示例中找到

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