Order of ClassPath

You can define multiple ClassPath, like

CLASSPATH=$CLASSPATH:/usr/local/apache/lucene/lucene-core-2.0.0.jar:/usr/local/apache/lucene/src/:/usr/local/apache/lucene/src/lucene-classes.jar:.
export CLASSPATH

But the order of ClassPath is important. Basically it is first come first server, if Java Interpreter find the class in the first class path, then it will ignore the the one in the later class path. See the detail from Oracle java doc

The order in which you specify multiple class path entries is important. The Java interpreter will look for classes in the directories in the order they appear in the class path variable. In the example above, the Java interpreter will first look for a needed class in the directory C:\java\MyClasses. Only if it doesn't find a class with the proper name in that directory will the interpreter look in the C:\java\OtherClasses directory.