com.google.sitebricks.conversion.generics

Class Generics

java.lang.Object

com.google.sitebricks.conversion.generics.Generics

public class Generics
extends Object

Constructor Summary

Constructors

Constructor and Description
Generics()

Method Summary

Methods

Modifier and Type	Method and Description
static Type	addWildcardParameters(Class<?> clazz) Returns a type representing the class, with all type parameters the unbound wildcard ("?").
static Type	capture(Type type) Applies capture conversion to the given type.
static Class<?>	erase(Type type) Returns the erasure of the given type.
static Type	getArrayComponentType(Type type) If type is an array type, returns the type of the component of the array.
static Type[]	getExactDirectSuperTypes(Type type) Returns the direct supertypes of the given type.
static Type	getExactFieldType(Field f, Type type) Returns the exact type of the given field in the given type.
static Type	getExactReturnType(Method m, Type type) Returns the exact return type of the given method in the given type.
static Type	getExactSuperType(Type type, Class<?> searchClass) With type a supertype of searchClass, returns the exact supertype of the given class, including type parameters.
static String	getTypeName(Type type) Returns the display name of a Type.
static Type	getTypeParameter(Type type, TypeVariable<? extends Class<?>> variable) Gets the type parameter for a given type that is the value for a given type variable.
static boolean	isSuperType(Type superType, Type subType) Checks if the capture of subType is a subtype of superType

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Generics

public Generics()

Method Detail

erase

public static Class<?> erase(Type type)

Returns the erasure of the given type.

addWildcardParameters

public static Type addWildcardParameters(Class<?> clazz)

Returns a type representing the class, with all type parameters the unbound wildcard ("?"). For example, addWildcardParameters(Map.class) returns a type representing Map<?,?>.

Returns:

• If clazz is a class or interface without type parameters, clazz itself is returned.
• If clazz is a class or interface with type parameters, an instance of ParameterizedType is returned.
• if clazz is an array type, an array type is returned with unbound wildcard parameters added in the the component type.

getExactSuperType

public static Type getExactSuperType(Type type,
                     Class<?> searchClass)

With type a supertype of searchClass, returns the exact supertype of the given class, including type parameters. For example, with class StringList implements List<String>, getExactSuperType(StringList.class, Collection.class) returns a ParameterizedType representing Collection<String>.

• Returns null if searchClass is not a superclass of type.
• Returns an instance of Class if type if it is a raw type, or has no type parameters
• Returns an instance of ParameterizedType if the type does have parameters
• Returns an instance of GenericArrayType if searchClass is an array type, and the actual type has type parameters

getTypeParameter

public static Type getTypeParameter(Type type,
                    TypeVariable<? extends Class<?>> variable)

Gets the type parameter for a given type that is the value for a given type variable. For example, with class StringList implements List<String>, getTypeParameter(StringList.class, Collection.class.getTypeParameters()[0]) returns String.

Parameters:

type - The type to inspect.

variable - The type variable to find the value for.

Returns:

The type parameter for the given variable. Or null if type is not a subtype of the type that declares the variable, or if the variable isn't known (because of raw types).

isSuperType

public static boolean isSuperType(Type superType,
                  Type subType)

Checks if the capture of subType is a subtype of superType

getArrayComponentType

public static Type getArrayComponentType(Type type)

If type is an array type, returns the type of the component of the array. Otherwise, returns null.

getExactDirectSuperTypes

public static Type[] getExactDirectSuperTypes(Type type)

Returns the direct supertypes of the given type. Resolves type parameters.

getExactReturnType

public static Type getExactReturnType(Method m,
                      Type type)

Returns the exact return type of the given method in the given type. This may be different from m.getGenericReturnType() when the method was declared in a superclass, of type is a raw type.

getExactFieldType

public static Type getExactFieldType(Field f,
                     Type type)

Returns the exact type of the given field in the given type. This may be different from f.getGenericType() when the field was declared in a superclass, of type is a raw type.

capture

public static Type capture(Type type)

Applies capture conversion to the given type.

getTypeName

public static String getTypeName(Type type)

Returns the display name of a Type.