How to run Java in compatibility mode?

java java-8 compatibility-mode
Rajesh Kumar Yadav picture Rajesh Kumar Yadav · May 4, 2016 · Viewed 7.5k times · Source

Does Java support running in compatibility mode? In other words if we have JDK 8 install on system, can it be configured to run my application on 7 or previous release using the same installation ?

I can give one example like IE-11 can be switch to run as IE 8, 9, or 10 based on the compatibility option.

Answer

GdR picture GdR · May 4, 2016

I agree with the comment of Kayaman. There are 2 types of incompatibilities that could occur: bytecode changes (some feature supported in 8 and not in 7 - new Java versions tend to be upward compatible - so 8 will be able to run all 7-targeted code) and library changes which is more problematic.

If you have compiled with Java 8 targeting 7+, your bytecode will be compatible with Java 7 JVM, but you have no guarantee that it will run with Java 7 libraries.

Your best bet is then to compile and run with Java 7 - and it will (most probably) run with Java 8.

Then there are other changes that may impact your application (GC performance for instance).

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