GWT migration

We’re using GWT 2.0.3 on one of our projects. Today we’ve noticed a very strange defect in IE8 and decided to upgrade to the latest version which is now 2.2.0.

So initially we’ve got three modules with four languages specified. All this stuff was referencing GWT 2.0.3 and gwt-maven-plugin of version 1.2 was used for compilation.

During upgrade the following changes were done:

  1. Referenced GWT version was changed to 2.2.0
  2. gwt-maven-plugin version was changed to 2.1.0-1
  3. Scope of the com.google.gwt.gwt-dev was changed from test to compile otherwise I was getting “java.lang.NoClassDefFoundError: com/google/gwt/core/ext/GeneratorExt”
  4. Refactored module inheritence slightly otherwise I was getting: “Element ‘property-provider’ beginning on line 75 contains unexpected attribute ‘generator'”

So the migration ran pretty smoothly and I haven’t noticed any new problems in the application itself. But this migration has brought a huge benefit in compilation time.

Module 2.0.3 compilation
(in seconds)
2.2.0 compilation
(in seconds)
Difference
Module 1 611 390 -36%
Module 2 703 394 -44%
Module 3 118 142 +20%
Total 1617 1064 -34%

GWT compilation speed is the major factor which affects build time on our project. And this upgrade reduces the whole compilation time by 34%. You definitely should consider upgrading taking into account new tasty features of GWT 2.2.0.