Backport Java 5/6 features to Java 1.4?

Question

We are stuck with Java2SE v1.4 till the end of 2010. That's really nasty, but we can't help it. What options do we have to use some of the new features already now? I can think of several ways like

• changing the bytecode, e.g. using Retrotranslator or Retroweaver.

• backport of libraries, e.g. Concurrent Backport, but this does not help for generics.

• emulation of Java 5 features, e.g. checked Collections, Varargs with helper methods, etc.

• changing source code by precompilation, stripping all 1.5 stuff before final compilation, e.g. using Declawer can do this.

I am most interested in very positive experience with it in production environments using Weblogic and "real" stuff.

Answer 1

sourcecode precompilation, stripping all 1.5 stuff before final compilation and deployment. Are there any tools which can do this?

Yes. They're called Retrotranslator or Retroweaver. Apart from Generics (which only exist for the compiler's sake anyway), you cannot simply "strip 1.5 stuff". Enums (and maybe also some other features) have to be replaced with functionally equivalent code. Which is exactly what those tools do.

Answer 2

You can code with JDK 1.5 features and target JDK 1.4 at compile time. See available Javac options. However, most libraries are now using JDK 1.5 code, so you'll be stuck with old libs.

Answer 3

It worth noting that while Java 1.4 has been EOL for some time. Java 5.0 will be EOL Oct 8th, 2009. If anyone is promising you Java 5.0 by 2010, I would ask why?!

Answer 4

To simulate annotations in java 1.4 you can use http://xdoclet.sourceforge.net/xdoclet/index.html

Answer 5

write a program currencyconverter that asks the user to inter todays between u.s. dollars and the euro.then the program reads u.s. dollars values and converts each to euro values.stopwhen the user enters q.