Annotation Interface PostConstructionInitializer

@Target(METHOD) @Retention(RUNTIME) public @interface PostConstructionInitializer
Marks a method as a post-construction initializer. The WPILib compiler plugin will check for uses of methods with this annotation and report a compiler error if the method is not called after the object is constructed.

Limitations of this annotation:

  • Initializer methods must be called on the variable directly. They cannot be detected if called indirectly (e.g., on an object returned by a method) 
    // This is OK
Foo foo = new Foo();
foo.init();

// This is not OK
Box box = new Box(new Foo());
box.getFoo().init();
  • Static initializer methods must accept exactly one parameter of the type that defines the static method (they cannot accept a parameter of a supertype or derived type).
  • Static initializer methods with multiple parameters of the initialized type must annotate one of them with PostConstructionInitializer.InitializedParam to disambiguate for the compiler.

Errors reported by the compiler plugin may be suppressed by annotating the offending method with SuppressWarnings("PostConstructionInitializer") or SuppressWarnings(PostConstructionInitializer.SUPPRESSION_KEY). This is intended to be used in tests to allow runtime error handling code to be tested, but may also be used to suppress spurious warnings in production code.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static @interface 
    PostConstructionInitializer.InitializedParam
    Marks a specific parameter in a static initializer method as being the initialized object.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    SUPPRESSION_KEY
    The string key to use in SuppressWarnings annotations to suppress compiler error messages related to this annotation.

  • Field Details