File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
The moose likes Java in General and the fly likes Class File Information Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Java » Java in General
Bookmark "Class File Information" Watch "Class File Information" New topic

Class File Information

Saurav Chetia

Joined: Oct 28, 2002
Posts: 10
If I have a java class file and I want to know about it's version(major and minor) how to obtain those values ?
I used package. Using the ClassFile class I tried to get the major and minor versions but I get the default values of MajorVersion : 45 , and MinorVersion : 3.
I used the ClassFile constructor with InputStream argument.
Can someone tell me what am I am I missing here ?
Or else please suggest some other technique to get those information.
Michael Morris
Ranch Hand

Joined: Jan 30, 2002
Posts: 3451
Hi Saurav,
See if this doesn't work:

Michael Morris

Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius - and a lot of courage - to move in the opposite direction. - Ernst F. Schumacher
Saurav Chetia

Joined: Oct 28, 2002
Posts: 10
Thanks Michael!
That was a simple method to obtain information from a class file.
I just had doubt related with JVM implementation of JDK versions and the Class file format supported. Got the information from the Sun's JVM Specification.
Thanks again
I agree. Here's the link:
subject: Class File Information
It's not a secret anymore!