Class file format java7

Alex Buckley alex.buckley at
Wed Feb 23 11:52:48 PST 2011

Last week, a Maintenance Review was started for JSR 924, the Java 
Virtual Machine Specification.

This Maintenance Review proposes the "Java SE 7 Edition" of the Java 
Virtual Machine Specification. There are numerous changes since the last 
Maintenance Review in 2004, including to the class file format.

The changes from JSR 292 are _not_ integrated because, of course, they 
are not yet final. They will be integrated before Java SE 7 goes final.

The Maintenance Review is available on A comprehensive change 
log is provided.

If you have substantive technical comments about the specific changes 
proposed for the Java SE 7 Edition, please send them to me directly. (I 
am the Maintenance Lead for JSR 924.)

I hope that lambda-dev subscribers interested in the class file format 
will find the proposed Java Virtual Machine Specification helpful. 
Please note that further discussion of any kind about the Java Virtual 
Machine Specification on lambda-dev is inappropriate.


On 2/23/2011 8:35 AM, Brian Goetz wrote:
> Classfile changes for Java SE 7 are being driven by JSR-292.  I think 
> they have or are about to go to public review?  Check the JCP website 
> for JSR-292, and watch John Rose's blog for announcements.
> On 2/23/2011 11:02 AM, Roel Spilker wrote:
>> Hi all,
>> In java7 some modifications will be made to the class file format. At
>> least there will be some new constant types added to the constant
>> pool. For instance CONSTANT_MethodHandle for method handles.
>> Is there already documentation available? I'm looking for something like
>> If not, when can this be expected? I don't need a final version, but I
>> would like to start working on java7 compliancy.
>> Roel Spilker
>> P.S. Can anybody tell me what happened to constant type #17?

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