Mapreduce程序导致错误

Question

尝试Java MapReduce问题。当我用下面的命令编译代码时，我得到一些错误，他们列在下面..请帮助我。在此先感谢

的源代码

package cvkumar.hadoopmr; 
import java.io.IOException; 
import java.util.StrinTokenizer; 
import org.apache.hadoop.fs.Path; 
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 org.apache.hadoop.io.IntWritable; 
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.input.KeyValueTextInputForm; 
import org.apache.hadoop.mapreduce.lib.output.FileOutFormat; 
import org.apache.hadoop.util.GenericOptionsParser; 

public class Dictionary 
{ 
    public static class WordMapper extends Mapper <Text, Text, Text, Text> 
    { 
     private Text word = new Text(); 
     public void map(Text key, Text value, Context context) 
      throws IOException, InterruptedException 
     { 
      StringTokenizer itr = new StringTokenizer(value.toString(),","); 
      while (itr.hasMoreTokens()) 
      { 
       word.set(itr.nextToken()); 
       context.write(key,word); 
      } 
     } 
    } 
    public static class AllTranslationsReducer 
     extends Reducer<Text,Text,Text,Text> 
    { 
      private Text result = new Text(); 
      public void reduce(Text key, Iterable<Text> values,Context context) 
     throws IOException, InterruptedException 
      { 
       String translations = ""; 
       for (Text val : values) 
       { 
        translations += "|"+val.toString(); 
       } 
       result.set(translations); 
       context.write(key, result); 
      } 
     } 

    public static void main(String[] args) throws Exception 
    { 
      Configuration conf = new Configuration(); 
      Job job = new Job(conf, "dictionary"); 
      job.setJarByClass(Dictionary.class); 
      job.setMapperClass(WordMapper.class); 
      job.setReducerClass(AllTranslationsReducer.class); 
      job.setOutputKeyClass(Text.class); 
      job.setOutputValueClass(Text.class); 
      job.setInputFormatClass(KeyValueTextInputFormat.class); 
      //FileInputFormat.addInputPath(job, new Path("/tmp/hadoop-cscarioni/dfs/name/file")); 
      //FileOutputFormat.setOutputPath(job, new Path("output")); 
     FileInputFormat.addInputPath(job, new Path(args[0])); 
     FileOutputFormat.setOutputPath(job, new Path(args[1])); 
      System.exit(job.waitForCompletion(true) ? 0 : 1); 
     } 
} 

错误

$ javac的-classpath Hadoop的核心1.2.1.jar -d ./Dictionary ./cvkumar/hadoopmr/ Dictionary.java

hadoop@hadoop-Vostro1310:~/hadoop-1.2.1$ javac -classpath hadoop-core-1.2.1.jar -d ./Dictionary ./cvkumar/hadoopmr/Dictionary.java 
./cvkumar/hadoopmr/Dictionary.java:3: cannot find symbol 
symbol : class StrinTokenizer 
location: package java.util 
import java.util.StrinTokenizer; 
       ^
./cvkumar/hadoopmr/Dictionary.java:15: cannot find symbol 
symbol : class KeyValueTextInputForm 
location: package org.apache.hadoop.mapreduce.lib.input 
import org.apache.hadoop.mapreduce.lib.input.KeyValueTextInputForm; 
              ^
./cvkumar/hadoopmr/Dictionary.java:16: cannot find symbol 
symbol : class FileOutFormat 
location: package org.apache.hadoop.mapreduce.lib.output 
import org.apache.hadoop.mapreduce.lib.output.FileOutFormat; 
              ^
./cvkumar/hadoopmr/Dictionary.java:27: cannot find symbol 
symbol : class StringTokenizer 
location: class cvkumar.hadoopmr.Dictionary.WordMapper 
      StringTokenizer itr = new StringTokenizer(value.toString(),","); 
      ^
./cvkumar/hadoopmr/Dictionary.java:27: cannot find symbol 
symbol : class StringTokenizer 
location: class cvkumar.hadoopmr.Dictionary.WordMapper 
      StringTokenizer itr = new StringTokenizer(value.toString(),","); 
            ^
./cvkumar/hadoopmr/Dictionary.java:61: setInputFormatClass(java.lang.Class<? extends org.apache.hadoop.mapreduce.InputFormat>) in org.apache.hadoop.mapreduce.Job cannot be applied to (java.lang.Class<org.apache.hadoop.mapred.KeyValueTextInputFormat>) 
      job.setInputFormatClass(KeyValueTextInputFormat.class); 
      ^
./cvkumar/hadoopmr/Dictionary.java:65: setOutputPath(org.apache.hadoop.mapred.JobConf,org.apache.hadoop.fs.Path) in org.apache.hadoop.mapred.FileOutputFormat cannot be applied to (org.apache.hadoop.mapreduce.Job,org.apache.hadoop.fs.Path) 
     FileOutputFormat.setOutputPath(job, new Path(args[1])); 
         ^
7 errors 

Answer 1

答案已经是t在这里，由java编译器。更改以下行：

线3：

import java.util.StringTokenizer; 

线15：

import org.apache.hadoop.mapreduce.lib.input.KeyValueTextInputFormat; 

线16：

import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; 

提示：如果您使用的是像一个IDE Eclipse或NetBeans，java编译错误应该已经很高了点亮并向您展示如何解决它们的提示。如果您不使用IDE，我强烈建议您这样做！由于您正在编写MapReduce程序，因此我建议使用Eclipse，您可以在其中找到hadoop plugin。