Hadoop問題:編譯WordCount程序報錯:class file for org.apache.commons.cli.Optio
第一次編譯Hadoop的程序，將安裝程序自帶的WordCount程序拿出來編譯執行，編譯時遇到如下錯誤：
Ubuntu@ubuntu:~/dev/wordcount$ javac -classpath /home/ubuntu/hadoop-1.0.4/hadoop-core-1.0.4.jar -d bin WordCount.java
WordCount.java:53: cannot access org.apache.commons.cli.Options
class file for org.apache.commons.cli.Options not found
String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
^
1 error
在網上搜索了一下，找到了原因，在 classpath 中再加上一個 jar 包即可：
ubuntu@ubuntu:~/dev/wordcount$ javac -classpath /home/ubuntu/hadoop-1.0.4/hadoop-core-1.0.4.jar:/home/ubuntu/hadoop-1.0.4/lib/commons-cli-1.2.jar -d bin WordCount.java
ubuntu@ubuntu:~/dev/wordcount$ ls bin/*.class
bin/WordCount.class bin/WordCount$IntSumReducer.class bin/WordCount$TokenizerMapper.class