Hadoop的java编译器无法找到文件

Question

命令提交：

javac -classpath usr/local/hadoop/share/hadoop/tools/lib/hadoop-core-0.20.204.0.jar:usr/local/hadoop/share/hadoop/tools/lib/commons-cli-1.2.jar -d compiled_programs grep_example/WordCount.java > out 2>error 

是否查看目录，这两个公* .jar和核心的* .jar存在于指定的目录。

错误：

grep_example/WordCount.java:4: error: package org.apache.hadoop.conf does not exist 
import org.apache.hadoop.conf.Configuration; 
          ^
grep_example/WordCount.java:5: error: package org.apache.hadoop.fs does not exist 
import org.apache.hadoop.fs.Path; 
         ^
grep_example/WordCount.java:6: error: package org.apache.hadoop.io does not exist 
import org.apache.hadoop.io.IntWritable; 
         ^
grep_example/WordCount.java:7: error: package org.apache.hadoop.io does not exist 
import org.apache.hadoop.io.Text; 
         ^
grep_example/WordCount.java:8: error: package org.apache.hadoop.mapreduce does not exist 
import org.apache.hadoop.mapreduce.Job; 
           ^
grep_example/WordCount.java:9: error: package org.apache.hadoop.mapreduce does not exist 
import org.apache.hadoop.mapreduce.Mapper; 

我在做什么错？ Ubuntu和Hadoop都是新手。

谢谢！

Answer 1

看起来像你的类路径不正确。您在每个图书馆的开始处都有usr/..。它应该是/usr/..

正确的命令：

javac \ 
    -classpath /usr/local/hadoop/share/hadoop/tools/lib/hadoop-core-0.20.204.0.jar:/usr/local/hadoop/share/hadoop/tools/lib/commons-cli-1.2.jar \ 
    -d compiled_programs \ 
    grep_example/WordCount.java \ 
    > out 2> error