Compiling GWT with Java 8 compiler, but keeping GWT code to only use Java 6 constructs - possible?

[Jean Barmash]

I'd like to upgrade my project to Java 8.  We use GWT 2.0.3.

I have read the updates about full support of Java 8, and understand that to fully support it, the GWT code generator needs to support all Java8 features. 

However, what I need is a bit different I am happy to freeze the code UI code that interacts with GWT to only use Java6 constructs, so I don't need the code generator to support Java8 features.  

Is this possible?   I.e. to get my project compiled with Java 8, if the GWT code is only using Java 6 features.  

Would love to hear some opinions, as well possibly an update on the full Java 8 support timelines.   I saw that there is a fork that tried to move along this path.  

Thanks,

Jean

[Thomas Broyer]

On Thursday, July 31, 2014 8:43:04 PM UTC+2, Jean Barmash wrote:

I'd like to upgrade my project to Java 8.  We use GWT 2.0.3.

I have read the updates about full support of Java 8, and understand that to fully support it, the GWT code generator needs to support all Java8 features. 

However, what I need is a bit different I am happy to freeze the code UI code that interacts with GWT to only use Java6 constructs, so I don't need the code generator to support Java8 features.  

Is this possible?   I.e. to get my project compiled with Java 8, if the GWT code is only using Java 6 features.

Absolutely.

AFAICT, you'd have to compile (javac) the classes with "-source 1.6 -target 1.6" too, so you'll have to have your client-side (GWT-compatible) and server-side code clearly separated.

 

Would love to hear some opinions, as well possibly an update on the full Java 8 support timelines.   I saw that there is a fork that tried to move along this path.

Java 8 support will unforteunately won't make it to GWT 2.7 to be released this summer. You'll have to wait for 3.0 (to be released this winter) 

[Jean Barmash]

Great, thanks!   I do have the UI code separate into separate maven build, so I should be able to use this approach.  

Jean