How to have a Guice module use another Guice module?
You would install your other modules protected void configure(){ install(new ProdDbModule()); install(new ProdPubSubModule()); // etc. }
guice
Accessing Guice injector in its Module?
This is an unusual request. Modules are more like config files than logic files: The Module is read to create the Injector, and then as soon as the Injector is created the module has done its job. For a simple Module, the Injector literally doesn’t exist until the Module is ready to be discarded. In … Read more
Can anyone provide a clear explanation of why Google Guice is useful?
Using Google Guice to provides ease in unit testing is only high-level advantage. Some people might not even use unit testing in their project. People has been using Spring/Dependency Injection more than only for unit testing. The low level advantage of using Google Guice is a matter of cohesion in your application, your classes in … Read more
Pass parameter to constructor with Guice
All the “Guice Constructor Parameter” answers seem to be incomplete in some way. Here is a complete solution, including usage and a visual: interface FooInterface { String getFooName(); } // Annotate the constructor and assisted parameters on the implementation class class Foo implements FooInterface { String bar; @Inject Foo(@Assisted String bar) { this.bar = bar; … Read more
Guice and properties files
You can bind properties using Names.bindProperties(binder(), getProperties()), where getProperties returns a Properties object or a Map<String, String> (reading the properties file as a Properties object is up to you). You can then inject them by name using @Named. If you had a properties file: foo=bar baz=true You could inject the values of those properties anywhere … Read more
Lombok – retain field’s annotation in constructor input params
In version v1.18.4 Lombok added support for copying specific annotations. Meaning, that if you put following setting to lombok.config: lombok.copyableAnnotations += com.google.inject.name.Named and apply following Lombok annotations to your class: @RequiredArgsConstructor(onConstructor = @__(@Inject)) public class Hello { @NonNull @Named(“my-name”) String name; } the @Named annotation should be copied to your generated constructor argument. Limitations: this … Read more
Java error: Found interface … but class was expected
This happens when your runtime classpath is different than your compile time classpath. When your application was compiled, a class (named SomeInterface in your question) existed as a class. When your application is running at compile time, SomeInterface exists as an interface (instead of a class.) This causes an IncompatibleClassChangeError to be thrown at runtime. … Read more
How to bind concrete classes?
This is the way to go: protected void configure() { bind(Door.class); bind(Window.class); bind(Roof.class); } Since they are concrete classes, as Guice says, you can’t bind them to themselves 🙂 Check out the Binder docs, it notes: bind(ServiceImpl.class); This statement does essentially nothing; it “binds the ServiceImpl class to itself” and does not change Guice’s default … Read more
How to specify a classifier in a gradle dependency’s dependency?
There is no simpler solution. You can shorten the code by using short dependency notation (e.g. “com.google.inject:guice:3.0:no_aop”).
The guice AbstractModule install method
install allows for composition: Within its configure method, FooModule may install FooServiceModule (for instance). This would mean that an Injector created based only on FooModule will include bindings and providers in both FooModule and FooServiceModule. You may see install used to split a Module into logical sub-modules for ease of readability or testing, or for … Read more