Java 7 - Diamond Operator

[Albert Attard]

Hi everyone,

The following error is returned when compiling code using the diamond operator (part of project coin in Java 7).

Syntax error on token "<", ? expected after this token

I am using the GWT 2.40 (Plugin - com.google.gwt.eclipse.sdkbundle_2.4.0.v201205091048-rel-r37).

The following fragment is a simple example of the diamond operator:

List<String> names = new ArrayList<>();

Question:

1. Does GWT support Java 7 features?  
2. What changed do I need to perform in order to have the Java 7 code working without having to change the source?
   
3. What other features from the latest Java 7 GWT does not support?

Thank you in advance for any input.

Albert Attard

[Thomas Broyer]

On Thursday, June 14, 2012 12:49:55 PM UTC+2, Albert Attard wrote:

Question:

1. Does GWT support Java 7 features?  

No.

Not yet. Though it will likely take some time.

 

1. What changed do I need to perform in order to have the Java 7 code working without having to change the source?
   

In terms of what should be done within GWT to make it support Java 7?

Well, first and foremost upgrade ECJ to a version that supports Java 7. Hopefully that would be enough to support the diamond operator, and possibly all other Java 7 features. "Switch on strings" would hwoever greatly benefit from a specific handling in GWT, to compile it to an equivalent switch in JS.

1. What other features from the latest Java 7 GWT does not support?

No single one. GWT uses a Java 6 parser, so it only supports Java 6.

[Albert Attard]

Thanks for your reply.

Albert

[Albert Attard]

The page (https://developers.google.com/web-toolkit/doc/latest/DevGuideCodingBasicsCompatibility) only mentions support for Java 1.5.  Sorry for the trouble, I missed it before.

I was looking for diamond operator before and found nothing, where my search criteria had to be different :(.  There are plenty of posts about this.

Thanks again,

Albert Attard

On Thursday, June 14, 2012 12:57:36 PM UTC+2, Thomas Broyer wrote: