Package com.jsunsoft.http

Class TypeReference<T>

java.lang.Object

com.jsunsoft.http.TypeReference<T>

All Implemented Interfaces:

Comparable<TypeReference<T>>

public class TypeReference<T>
extends Object
implements Comparable<TypeReference<T>>

This generic abstract class is used for obtaining full generics type information 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>>() { };
  

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	TypeReference()	Constructs a new generic type, deriving the generic type and class from type parameter.
	TypeReference(Type typeReference)	Constructs a new generic type, supplying the generic type information and deriving the class.

Method Summary

Modifier and Type	Method	Description
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.
boolean	equals(Object obj)
Class<?>	getRawType()	Returns the object representing the class or interface that declared the type represented by this generic type instance.
Type	getType()	Retrieve the type represented by the generic type instance.
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

TypeReference

protected TypeReference()

Constructs a new generic type, deriving the generic type and class from type parameter. Note that this constructor is protected, users should create a (usually anonymous) subclass as shown above.

Throws:

IllegalArgumentException - in case the generic type parameter value is not provided by any of the subclasses.

TypeReference

public TypeReference(Type typeReference)

Constructs a new generic type, supplying the generic type information and deriving the class.

Parameters:

typeReference - the generic type.

Throws:

IllegalArgumentException - if typeReference is null or not an instance of Class or ParameterizedType whose raw type is an instance of Class.

Method Detail

getType

public final Type getType()

Retrieve the type represented by the generic type instance.

Returns:

the actual type represented by this generic type instance.

getRawType

public final Class<?> getRawType()

Returns the object representing the class or interface that declared the type represented by this generic type instance.

Returns:

the class or interface that declared the type represented by this generic type instance.

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

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>

toString

public String toString()

Overrides:

toString in class Object