Guice , afterPropertiesSet

Question

Someone knows some way that how can I achieve the same functionality in Guice as the \'afterPropertiesSet\' interface in spring ? ( its a post construction hook )

Answer 1

By far the simplest solution, if you're using constructor injection and not doing anything too crazy, is to create a post-construction method and annotate it with @Inject:

final class FooImpl implements Foo {
  private final Bar bar;

  @Inject
  FooImpl(Bar bar) {
    this.bar = bar;

    ...
  }

  @Inject
  void init() {
    // Post-construction code goes here!
  }
}

When Guice provides FooImpl, it'll see it has an @Inject constructor, call it, and then search for methods annotated with @Inject and call those. The intended use case for this is setter injection, but even if an @Inject method has no params, Guice will call it.

I don't recommend using this if you're using setter or field injection to inject deps since I don't know if Guice makes any guarantees about the order in which @Inject methods are called (that is, your init() method might not be guaranteed to be called last). That said, constructor injection is the preferred approach anyway, so that should be a non-issue.