Class TypeReference<T>

java.lang.Object
io.webfolder.cdp.TypeReference<T>
All Implemented Interfaces:
Comparable<TypeReference<T>>

public abstract class TypeReference<T> extends Object implements Comparable<TypeReference<T>>
This generic abstract class is used for obtaining full generics type information by sub-classing; it must be converted to ResolvedType implementation (implemented by JavaType from "databind" bundle) to be used. Class is based on ideas from http://gafter.blogspot.com/2006/12/super-type-tokens.html, Additional idea (from a suggestion made in comments of the article) is to require bogus implementation of Comparable (any such generic interface would do, as long as it forces a method with generic type to be implemented). to ensure that a Type argument is indeed given.

Usage is by sub-classing: here is one way to instantiate reference to generic type List<Integer>:

  TypeReference ref = new TypeReference<List<Integer>>() { };
which can be passed to methods that accept TypeReference, or resolved using TypeFactory to obtain ResolvedType.
  • Field Details

    • _type

      protected final Type _type
  • Constructor Details

    • TypeReference

      protected TypeReference()
  • Method Details

    • getType

      public Type getType()
    • compareTo

      public int compareTo(TypeReference<T> o)
      The only reason we define this method (and require implementation of Comparable) is to prevent constructing a reference without type information.
      Specified by:
      compareTo in interface Comparable<T>