I would imagine that the availability of binary 1.4 compatibility should be enough for most users.
I don't see how there should be any problems so long as we continue to try and use the Java 1.4 libraries and the generics features of 1.5. I have tested out Retroweaver briefly in the past and it seemed to work well, but it would interesting to hear from anyone who has any hands on experience with using it.
+1 from me. Adrian. Vincent Hennebert wrote:
Hi Guys, I would like to raise this topic again: what about switching to Java 1.5 as a minimum requirement? The End of Life transition period for Java 1.4 will end on the 30th of October 2008 [1]. The next version of FOP (after 0.95) will probably not have been released by this time, so we could start using 1.5 features in the Trunk. [1] http://java.sun.com/j2se/1.4.2/download.html I don’t particularly expect any disagreement from a developer point of vue (who doesn’t want to use 1.5 features?), so in the end this will probably depend on the users’ reactions, but I thought I’d ask for opinions here first. According to the poll Jeremias made in October 2007 [2], only 14.3% of the users would think it’s a bad idea to switch to 1.5. A year later the percentage will probably have further decreased. [2] http://wiki.apache.org/xmlgraphics/UserPollOct2007 I guess a new poll will still be necessary. Or we could base it on lazy consensus: “If you still want Java 1.4 compatibility, speak up now!”. Anyway, even if 1.4 compatibility is still considered to be required, there are tools to convert 1.5 code into 1.4 compatible one. I’m mainly thinking of Retroweaver: http://retroweaver.sourceforge.net/ It’s BSD licensed, so IIC there wouldn’t be any problem to distribute it with FOP. Obviously it would be an (optional) compile-time dependency only. I haven’t personally tested it, but I’m told it’s working pretty well and it seems to be well maintained. Of course I’d volunteer to introduce it into the build system and see how it works. FWIW, it’s based on the ASM library, that I’ve had the opportunity to play with a few years ago, and what I can say is that it’s a really nice, strong, lightweight, easy to use library for manipulating class files. http://asm.objectweb.org/ Obviously we wouldn’t switch everything to 1.5 immediately. We would do it progressively, when fixing bugs or implementing new features. So it should be easy to check that the conversion is working properly by running the testsuite on a 1.4 jvm, before every commit. Also, we could restrain ourselves to features that are directly translatable to 1.4: generics, enhanced for loop, autoboxing/unboxing. Most of all we could stick to using methods from the Java standard library that are also available in the 1.4 version (and, for instance, not use the new concurrency package for now). Just having the possibility to use generics would give us tremendous benefits: simpler, cleaner, safer code, more easily understandable, more easily maintainable, etc. I can’t wait anymore to use those features. So, WDYT? Thanks, Vincent