public class TypeLiteral<T> extends Object
T
. Java doesn't yet provide a way to
represent generic types, so this class does. Forces clients to create a
subclass of this class which enables retrieval the type information even at
runtime.
For example, to create a type literal for List<String>
, you can
create an empty anonymous inner class:
TypeLiteral<List<String>> list = new TypeLiteral<List<String>>() {};
Along with modeling generic types, this class can resolve type parameters.
For example, to figure out what type keySet()
returns on a Map<Integer, String>
, use this code:
TypeLiteral<Map<Integer, String>> mapType
= new TypeLiteral<Map<Integer, String>>() {};
TypeLiteral<?> keySetType
= mapType.getReturnType(Map.class.getMethod("keySet"));
System.out.println(keySetType); // prints "Set<Integer>"
Modifier | Constructor and Description |
---|---|
protected |
TypeLiteral()
Constructs a new type literal.
|
Modifier and Type | Method and Description |
---|---|
boolean |
equals(Object o) |
static <T> TypeLiteral<T> |
get(Class<T> type)
Gets type literal for the given
Class instance. |
static TypeLiteral<?> |
get(Type type)
Gets type literal for the given
Type instance. |
List<TypeLiteral<?>> |
getExceptionTypes(Member methodOrConstructor)
Returns the resolved generic exception types thrown by
constructor . |
TypeLiteral<?> |
getFieldType(Field field)
Returns the resolved generic type of
field . |
List<TypeLiteral<?>> |
getParameterTypes(Member methodOrConstructor)
Returns the resolved generic parameter types of
methodOrConstructor . |
Class<? super T> |
getRawType()
Returns the raw (non-generic) type for this type.
|
TypeLiteral<?> |
getReturnType(Method method)
Returns the resolved generic return type of
method . |
TypeLiteral<?> |
getSupertype(Class<?> supertype)
Returns the generic form of
supertype . |
Type |
getType()
Gets underlying
Type instance. |
int |
hashCode() |
String |
toString() |
protected TypeLiteral()
Clients create an empty anonymous subclass. Doing so embeds the type parameter in the anonymous class's type hierarchy so we can reconstitute it at runtime despite erasure.
public final Class<? super T> getRawType()
public final Type getType()
Type
instance.public static TypeLiteral<?> get(Type type)
Type
instance.public static <T> TypeLiteral<T> get(Class<T> type)
Class
instance.public TypeLiteral<?> getSupertype(Class<?> supertype)
supertype
. For example, if this is ArrayList<String>
, this returns Iterable<String>
given the input Iterable.class
.supertype
- a superclass of, or interface implemented by, this.public TypeLiteral<?> getFieldType(Field field)
field
.field
- a field defined by this or any superclass.public List<TypeLiteral<?>> getParameterTypes(Member methodOrConstructor)
methodOrConstructor
.methodOrConstructor
- a method or constructor defined by this or any supertype.public List<TypeLiteral<?>> getExceptionTypes(Member methodOrConstructor)
constructor
.methodOrConstructor
- a method or constructor defined by this or any supertype.public TypeLiteral<?> getReturnType(Method method)
method
.method
- a method defined by this or any supertype.Copyright © 2006-2016 Google, Inc.. All Rights Reserved.