Re: classpath class loading

[Mark Wielaard]

Hi,

On Sat, 2002-12-07 at 20:29, Jakob Praher wrote:
> I am starting on doing some code sketches for an implementation of the
> optional package versioning, which is done @ the Manifest level, where
> things entries like:
> 
> Extension-Name: org.foobar
> Specification-Vendor: Foobar ...
> Specification-Version: 1.0
> Implementation-Vendor-Id: com.xyz.foobar
> Implementation-Vendor: xyz company
> Implementation-Version: 1.0
> 
> for that I need some ultra fast way of handling jar files - and would
> like to ask, how the classpath project does the default loading of jar
> files in the classpath classloader?
> 
> - Are you using native code?

No, we use the normal java.util.jar clasees to access this information.
java.util.jar uses the java.util.zip classes which are written in java.
But some VM implementations that use GNU Classpath (such as [lib]gcj)
come with C/C++ based implementations of java.util.zip.

> - Are you using the default java.util.jar File?

Yes. Just java.util.jar.Jar.getManifest().

> I have looked at the source, but I could find the *real* stuff in the
> ClassLoader ..
> 
> any pointers are appreciated.

Only the java.net.URLClassLoader actually construct the package
information at the moment. Look at the methods findClass() and
definePackage() in that class.

Cheers,

Mark