#780 improve Java 1.5 compatibitility

[Anonymous]

I have several problems using JabRef on MacOS 10.5 (PowerPC) with Java 1.5 (1.6 is not available). I can not edit entries, because of an exepetion which happens by using the editor.
--> Exception in thread "AWT-EventQueue-0" java.lang.NoSuchMethodError: java.lang.String.isEmpty()Z
Well, the method java.lang.String.isEmpty() was introduced in Java 1.6 but it is incompatible to Java 1.5. But this can be fixed by using "some string".length()==0 what detects if the string is empty.

Also the problem is explained here: http://youtrack.jetbrains.com/issue/SCL-370

[Oliver Kopp]

We plan to upgrade the Java level to 1.6 and even 1.7 to be sure to be able to use new external libraries. Can you check whether you can update your Java installation to 1.6 oder even 1.7? http://stackoverflow.com/questions/613175/java-6-on-mac-powerpc-with-mac-os-x-10-4 and https://wikis.oracle.com/display/OpenJDK/BSDPort

The currently used jgoodies library 1.5.1 requires Java 6. Even with our downgrade in the code itself, JabRef 2.9 beta 2 probably won't run at your machine.

[Oliver Kopp]

We have a new branch "java5" in the git repository. We had to remove following features:
- MrdLib lookup
- FreeCite importer
- Send as email
- System tray

If you want, I can build a version compatible with java5. In case there is no demand, we will not release a special version compatible with Java 1.5.