Package com.complexible.common.inject

Class OptionalConstructorParam<T>

java.lang.Object
com.complexible.common.inject.OptionalConstructorParam<T>
All Implemented Interfaces:
Supplier<T>
public final class OptionalConstructorParam<T> extends Object implements Supplier<T>

Workaround for optional constructor parameters with Guice. Modeled after the Guava Optional class, but you cannot create your own Optional because the constructor is private, so just adopting the look and feel of it.

Unfortunately, this does not support optional bindings which use @Named; that annotation on the value in the constructor, eg:

public Foo(@Named("bar") OptionalConstructorParam<MyObject> theParam)

Because the @Inject is inside OptionalConstructorParam and that's where the injection actually takes place, the @Named annotation is essentially ignored. If you could place @Named inside this class, with a parameterized value for the name, that would work as expected, but annotation values have to be consts, so there's no way to pass in the name to the annotation. So if you want to use @Named w/ an optional constructor parameter, you basically have to duplicate the Guice part of this class locally and use the @Named annotation explicitly.

Since:
0.6.5
Version:
4.0
Author:
Michael Grove
See Also:

  • Constructor Details

    • OptionalConstructorParam

      @Inject public OptionalConstructorParam()

    • OptionalConstructorParam

      public OptionalConstructorParam(T theValue)

  • Method Details

    • get

      public T get()
      Specified by:
      get in interface Supplier<T>

    • or

      public T or(T theDefault)

    • or

      public T or(Supplier<? extends T> theDefault)

    • orNull

      public T orNull()

    • asOptional

      public Optional<T> asOptional()

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • isPresent

      public boolean isPresent()

    • create

      public static <T> OptionalConstructorParam<T> create(T theValue)