public static void main(String[] args) { List list = PackageUtils.getClasseNamesInPackage( "C:/j2sdk1.4.1_02/lib/mail.jar", "com.sun.mail.handlers"); System.out.println(list); /* * output : * * Jar C:/j2sdk1.4.1_02/lib/mail.jar looking for com/sun/mail/handlers * Found com.sun.mail.handlers.text_html.class Found * com.sun.mail.handlers.text_plain.class Found * com.sun.mail.handlers.text_xml.class Found * com.sun.mail.handlers.image_gif.class Found * com.sun.mail.handlers.image_jpeg.class Found * com.sun.mail.handlers.multipart_mixed.class Found * com.sun.mail.handlers.message_rfc822.class * [com.sun.mail.handlers.text_html.class, * com.sun.mail.handlers.text_xml.class, com * .sun.mail.handlers.image_jpeg.class, , * com.sun.mail.handlers.message_rfc822.class] */ }