Open Source Java

[SamuraiCrow]

The trouble is in the porting.  Sun's code will likely only work on Linux.  Amiga has a few virtual machines that will work but the Swing, AWT, and similar such GUI classes haven't been ported yet.

[SamuraiCrow]

AARGH!  Without the classes Java is worthless!  We already have versions of the core.  We need the classes.  Maybe somebody should look into GNU ClassPath.

[SamuraiCrow]

@Karlos

Actually, GCJ can compile Java directly to machine language so the code can theoretically outperform a JIT.  However, the GNU ClassPath isn't as well optimized as Sun's classes.

[SamuraiCrow]

@smithy

There is a licence fee that must be paid for distribution of the Java Classes.  That's why AmigaDE didn't ship with them by default but, instead, required you to download them from Sun's site.

[SamuraiCrow]

smithy wrote:

SamuraiCrow wrote:
@smithy

There is a licence fee that must be paid for distribution of the Java Classes.  That's why AmigaDE didn't ship with them by default but, instead, required you to download them from Sun's site.

Ahhhh.. I didn't know that... but hopefully this will be covered in the open source terms - otherwise it won't really be open source!

That's just the point.  It WON'T likely be completely open-source.  Only the VM itself will be open-source.  This is just an attempt by Sun to disarm the advantages of GCJ over its own JIT.

[SamuraiCrow]

@Karlos

GCJ is based on GCC so it generates code just as well as the C++ that CCJ uses as an intermediate code.  Likewise, AFAIK, GNU ClassPath is implemented in C++ rather than Java.

[SamuraiCrow]

smithy wrote:

You are talking about the difference between using a JIT JVM and a non-JIT JVM.  But this has nothing to do at all with GCJ because GCJ is just a compiler - it compiles Java source code into bytecode.  It doesn't attempt to run it, so no JIT is involved or needed.

You can run bytecode created by GCJ on any compliant JVM, JIT or not.  There is no need to recompile it based on whether you use a JIT JVM.

So static or dynamic compilation doesn't really apply here, because one, or both can be done, it's up to you.

My original question was, how does Sun's decision to open up it's JVM impact GCJ, a source-compiler?

The difference is that GCJ can compile bytecode into native binary.  It can also compile source into native binary.  It is a static compiler based on GCC and, as such, is GPL so no Linux distro would need to do without it for reasons of licence incompatibiltiy.