ubuntu - hadoop Java编译器无法找到文件

Question

提交的命令:

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

检查了目录后，commons * .jar和core * .jar都存在于指定目录中。

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;

我究竟做错了什么？ Ubuntu和Hadoop的新功能。

谢谢!!

Answer 1

看起来您的类路径不正确。您在每个库的开头usr/..。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