Class GsonTypes

java.lang.Object

com.google.gson.internal.GsonTypes

public final class GsonTypes
extends Object

Static methods for working with types.

Author:

Bob Lee, Jesse Wilson

Method Summary

Modifier and Type	Method	Description
static GenericArrayType	arrayOf(Type componentType)	Returns an array type whose elements are all instances of componentType.
static Type	canonicalize(Type type)	Returns a type that is functionally equal but not necessarily equal according to Object.equals().
static boolean	equals(Type a, Type b)	Returns true if a and b are equal.
static Type	getArrayComponentType(Type array)	Returns the component type of this array type.
static Type	getCollectionElementType(Type context, Class<?> contextRawType)	Returns the element type of this collection type.
static Type[]	getMapKeyAndValueTypes(Type context, Class<?> contextRawType)	Returns a two element array containing this map's key and value types in positions 0 and 1 respectively.
static Class<?>	getRawType(Type type)
static ParameterizedType	newParameterizedTypeWithOwner(Type ownerType, Class<?> rawType, Type... typeArguments)	Returns a new parameterized type, applying typeArguments to rawType and enclosed by ownerType.
static boolean	requiresOwnerType(Type rawType)	Whether an owner type must be specified when constructing a ParameterizedType for rawType.
static Type	resolve(Type context, Class<?> contextRawType, Type toResolve)
static WildcardType	subtypeOf(Type bound)	Returns a type that represents an unknown type that extends bound.
static WildcardType	supertypeOf(Type bound)	Returns a type that represents an unknown supertype of bound.
static String	typeToString(Type type)

Methods inherited from class Object

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

Method Details

newParameterizedTypeWithOwner

public static ParameterizedType newParameterizedTypeWithOwner(Type ownerType,
 Class<?> rawType,
 Type... typeArguments)

Returns a new parameterized type, applying typeArguments to rawType and enclosed by ownerType.

Returns:

a parameterized type.

arrayOf

public static GenericArrayType arrayOf(Type componentType)

Returns an array type whose elements are all instances of componentType.

Returns:

a generic array type.

subtypeOf

public static WildcardType subtypeOf(Type bound)

Returns a type that represents an unknown type that extends bound. For example, if bound is CharSequence.class, this returns ? extends CharSequence. If bound is Object.class, this returns ?, which is shorthand for ? extends Object.

supertypeOf

public static WildcardType supertypeOf(Type bound)

Returns a type that represents an unknown supertype of bound. For example, if bound is String.class, this returns ? super String.

canonicalize

public static Type canonicalize(Type type)

Returns a type that is functionally equal but not necessarily equal according to Object.equals().

getRawType

public static Class<?> getRawType(Type type)

equals

public static boolean equals(Type a,
 Type b)

Returns true if a and b are equal.

typeToString

public static String typeToString(Type type)

getArrayComponentType

public static Type getArrayComponentType(Type array)

Returns the component type of this array type.

Throws:

ClassCastException - if this type is not an array.

getCollectionElementType

public static Type getCollectionElementType(Type context,
 Class<?> contextRawType)

Returns the element type of this collection type.

Throws:

IllegalArgumentException - if this type is not a collection.

getMapKeyAndValueTypes

public static Type[] getMapKeyAndValueTypes(Type context,
 Class<?> contextRawType)

Returns a two element array containing this map's key and value types in positions 0 and 1 respectively.

resolve

public static Type resolve(Type context,
 Class<?> contextRawType,
 Type toResolve)

requiresOwnerType

public static boolean requiresOwnerType(Type rawType)

Whether an owner type must be specified when constructing a ParameterizedType for rawType.

Note that this method might not require an owner type for all cases where Java reflection would create parameterized types with owner type.