public static boolean inJdkInternalform(@InternalForm String classname) {
    return classname.startsWith("java/")
        || classname.startsWith("com/oracle/")
        || classname.startsWith("com/sun/")
        || classname.startsWith("javax/")
        || classname.startsWith("jdk/")
        || classname.startsWith("org/ietj/")
        || classname.startsWith("org/jcp/")
        || classname.startsWith("org/omg/")
        || classname.startsWith("org/w3c/")
        || classname.startsWith("org/xml/")
        || classname.startsWith("sun/")
        || classname.startsWith("sunw/");
  }
public static boolean inJdkInternalform(@InternalForm String classname) {
    return classname.startsWith("java/")
        || classname.startsWith("com/oracle/")
        || classname.startsWith("com/sun/")
        || classname.startsWith("javax/")
        || classname.startsWith("jdk/")
        || classname.startsWith("org/ietj/")
        || classname.startsWith("org/jcp/")
        || classname.startsWith("org/omg/")
        || classname.startsWith("org/w3c/")
        || classname.startsWith("org/xml/")
        || classname.startsWith("sun/")
        || classname.startsWith("sunw/");
  }
public static boolean inJdkInternalform ( @ InternalForm String classname ) { return classname . startsWith ( "java/" ) || classname . startsWith ( "com/oracle/" ) || classname . startsWith ( "com/sun/" ) || classname . startsWith ( "javax/" ) || classname . startsWith ( "jdk/" ) || classname . startsWith ( "org/ietj/" ) || classname . startsWith ( "org/jcp/" ) || classname . startsWith ( "org/omg/" ) || classname . startsWith ( "org/w3c/" ) || classname . startsWith ( "org/xml/" ) || classname . startsWith ( "sun/" ) || classname . startsWith ( "sunw/" ) ; }
Returns whether or not the class is part of the JDK (rt.jar).

@param classname the class to test, in internal form
@return true iff the class is part of the JDK (rt.jar)
Returns whether or not the class is part of the JDK ( rt . jar ) .