question: public boolean isJavaLibraryClass ( ) { if ( name . startsWith ( "java." ) || name . startsWith ( "sun." ) || name . startsWith ( "javax." ) || name . startsWith ( "com.sun." ) || name . startsWith ( "org.omg." ) || name . startsWith ( "org.xml." ) ) return true ; return false ; }
target:  Sometimes we need to know which class is a JDK class. There is no simple way to distinguish a user class and a JDK class, here we use the package prefix as the heuristic.