javac -classpath /opt/hadoop-1.2.1/hadoop-core-1.2.1.jar:/opt/hadoop-1.2.1/lib/commons-cli-1.2.jar -d word_count_class/WordCount.java
javac: not a directory: word_count_class/WordCount.java
Usage: javac <options> <source files>
use -help for a list of possible options
怎么解决呀！
