Miscellaneous Features & Improvements

The GWT class has two new convenience methods

• GWT.getVersion(): reports what version of GWT was used to compile your application.
• GWT.isClient(): can be used to detect whether shared code is running in the browser (as opposed to on a server).

Call Java constructors from JSNI code

Java constructors can now be called directly from JSNI via the ::new method reference.

Access underlying JS object when catching a JavaScriptException

The JavaScriptException class has been improved to provide access to the underlying JS object when catching the exception.

Improvements or changes in usage to JRE classes

• Use Duration.currentTimeMillis() instead of System.currentTimeMillis(), since long is now emulated.
• Arrays.asList() is a really efficient array-backed collection; if you already have an array sitting around, it allows you to avoid the linear-time copy of all the elements.

Improvements to JUnit Testing and Benchmark components

• Added GWTTestSuite classes to optimize the order in which GWTTestCases are executed.
• Running JUnit tests over many test classes at once can be sped up remarkably by organizing test classes into GWTTestSuites.
• Benchmarks have moved out of com.google.gwt.junit to com.google.gwt.benchmarks; existing client code will need to reorganize imports to the correct package. The Range class has been completely removed in favor of java.lang.Iterable.
• The setUp/tearDown methods have now been replaced by gwtSetUp/gwtTearDown.
• New -manual web mode testing allows you to target the running test with any browser of your choice. See the Running your test in manual mode section in the developer guide for more details.

Application creator now creates a default css file

If your application's name is MyApp, then the default css file will be named MyApp.css.

Binary only annotations can be used in translatable source

Of course, this is in addition to source-only annotations.

Generators Improvements

• Expose Java 1.5 constructs like annotations and generics to Generator authors
• Generators can now mark Artifacts created by GeneratorContext.tryCreateResource() as being private; these files will be emitted into the module's auxiliary directory. This is a change that ties into the new Linker subsystem introduced in 1.5.
• Generators can now send custom Artifact instances to the Linker stack via GeneratorContext.commitArtifact(). This change also ties into the new Linker subsystem.

New

<rename-to>

module XML tag

The module XML file now supports an optional attribute "rename-to" which will change the name of the module produced by the compiler. This allows you to do such things as create drop-in replacements for your module by creating various working modules that can be renamed to your standard module name.

Updated Locale-specific components for standards compliance

• Upgraded DateTimeConstants data to CLDR 1.51, and added the firstDayOfTheWeek and weekendRange formatting symbols.
• Removed dependency on java.util.Locale in LocalizableGenerator for BCP47 compatibility

Zero-config Lightweight Performance Metrics

Design document can be found here.

• Provides data about the bootstrap process and RPC subsystem in code paths where user code cannot be added.
• Supports multiple modules on the same page.
• Incurs negligible overhead when no statistics collector function is defined.
• Minimizes observer effects by allowing for data aggregation to be performed in post-processing.
• Extensible: Users can follow the pattern to instrument their own code with custom metric events.