Hello, old java programs compile and run fine on newer java versions. You just need to use the right javac options (ie. -source and -bootclasspath) if you want to recompile old code with a newer compiler.
For instance, if you have a java 6 source code that you want to compile with java 8, call javac as below : $ javac -source 1.6 -bootclasspath /path/to/java6/rt.jar /path/to/foo.java Furthermore, to preserve compatibility with older java runtimes, the option -target must be used with -source and -bootclasspath. For instance, if you have a java 6 source code that you want to compile with java 8 and want it to be compatible with the JVM 6, 7 and 8, then, call javac as below : $ javac -target 1.6 -source 1.6 -bootclasspath /path/to/java6/rt.jar /path/to/foo.java -- SeB 2017-06-23 13:47 GMT+02:00 Jim Diamond <jim.diam...@acadiau.ca>: > On Fri, Jun 23, 2017 at 01:18 (-0400), B Watson wrote: > > > What I don't know (since I haven't paid attention to Java in 10+ years) > > is whether future versions of jdk/openjdk will always be compatible > > with code written for older versions (source code and/or compiled > > classes/jars). Will we get stuck having to still have openjdk version > > 7 in 10 years, because some piece of software written in Java can't be > > compiled or run with openjdk 8 and up? > > While I make every effort to avoid Java, there is one program I use > written in Java which I haven't yet managed to expunge from my life. > And every time there is a new version of Java out, I have to spend a > couple of days trying to figure out how to do something in the new > version, because the old version has deprecated methods or some > methods now don't do quite what they used to, or I'm no longer allowed > to call that method in that context, or ... > > My point is, I doubt I'm the only one who has this issue. I suppose > the difference is that most people maintaining Java programs do Java > programming 24/7/365, and so they can amortize this "learn the new > correct one and only way to do it" time over lots more code than I > can. > > Meanwhile, my 35-year old C programs happily compile and run with no > whining whatsoever. > > Cheers. > Jim > _______________________________________________ > SlackBuilds-users mailing list > SlackBuilds-users@slackbuilds.org > http://lists.slackbuilds.org/mailman/listinfo/slackbuilds-users > Archives - https://lists.slackbuilds.org/pipermail/slackbuilds-users/ > FAQ - https://slackbuilds.org/faq/ > >
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