org.springframework.core

Class GenericTypeResolver

java.lang.Object

org.springframework.core.GenericTypeResolver

public abstract class GenericTypeResolver
extends java.lang.Object

Helper class for resolving generic types against type variables.

Mainly intended for usage within the framework, resolving method parameter types even when they are declared generically.

Since:

1.0

Author:

Juergen Hoeller, Rob Harrop, Roy Clarkson

See Also:

GenericCollectionTypeResolver

Constructor Summary

Constructors

Constructor and Description
GenericTypeResolver()

Method Summary

Methods

Modifier and Type	Method and Description
static java.lang.reflect.Type	getTargetType(MethodParameter methodParam) Determine the target type for the given parameter specification.
static java.util.Map<java.lang.reflect.TypeVariable<?>,java.lang.reflect.Type>	getTypeVariableMap(java.lang.Class<?> clazz) Build a mapping of TypeVariable names to concrete Class for the specified Class.
static java.lang.Class<?>	resolveParameterType(MethodParameter methodParam, java.lang.Class<?> clazz) Determine the target type for the given generic parameter type.
static java.lang.Class<?>	resolveReturnType(java.lang.reflect.Method method, java.lang.Class<?> clazz) Determine the target type for the generic return type of the given method.
static java.lang.Class<?>	resolveReturnTypeArgument(java.lang.reflect.Method method, java.lang.Class<?> genericIfc) Resolve the single type argument of the given generic interface against the given target method which is assumed to return the given interface or an implementation of it.
static java.lang.Class<?>	resolveType(java.lang.reflect.Type genericType, java.util.Map<java.lang.reflect.TypeVariable<?>,java.lang.reflect.Type> typeVariableMap) Resolve the specified generic type against the given TypeVariable map.
static java.lang.Class<?>	resolveTypeArgument(java.lang.Class<?> clazz, java.lang.Class<?> genericIfc) Resolve the single type argument of the given generic interface against the given target class which is assumed to implement the generic interface and possibly declare a concrete type for its type variable.
static java.lang.Class<?>[]	resolveTypeArguments(java.lang.Class<?> clazz, java.lang.Class<?> genericIfc) Resolve the type arguments of the given generic interface against the given target class which is assumed to implement the generic interface and possibly declare concrete types for its type variables.

Methods inherited from class java.lang.Object

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

Constructor Detail

GenericTypeResolver

public GenericTypeResolver()

Method Detail

getTargetType

public static java.lang.reflect.Type getTargetType(MethodParameter methodParam)

Determine the target type for the given parameter specification.

Parameters:

methodParam - the method parameter specification

Returns:

the corresponding generic parameter type

resolveParameterType

public static java.lang.Class<?> resolveParameterType(MethodParameter methodParam,
                                      java.lang.Class<?> clazz)

Determine the target type for the given generic parameter type.

Parameters:

methodParam - the method parameter specification

clazz - the class to resolve type variables against

Returns:

the corresponding generic parameter or return type

resolveReturnType

public static java.lang.Class<?> resolveReturnType(java.lang.reflect.Method method,
                                   java.lang.Class<?> clazz)

Determine the target type for the generic return type of the given method.

Parameters:

method - the method to introspect

clazz - the class to resolve type variables against

Returns:

the corresponding generic parameter or return type

resolveReturnTypeArgument

public static java.lang.Class<?> resolveReturnTypeArgument(java.lang.reflect.Method method,
                                           java.lang.Class<?> genericIfc)

Resolve the single type argument of the given generic interface against the given target method which is assumed to return the given interface or an implementation of it.

Parameters:

method - the target method to check the return type of

genericIfc - the generic interface or superclass to resolve the type argument from

Returns:

the resolved parameter type of the method return type, or null if not resolvable or if the single argument is of type WildcardType.

resolveTypeArgument

public static java.lang.Class<?> resolveTypeArgument(java.lang.Class<?> clazz,
                                     java.lang.Class<?> genericIfc)

Resolve the single type argument of the given generic interface against the given target class which is assumed to implement the generic interface and possibly declare a concrete type for its type variable.

Parameters:

clazz - the target class to check against

genericIfc - the generic interface or superclass to resolve the type argument from

Returns:

the resolved type of the argument, or null if not resolvable

resolveTypeArguments

public static java.lang.Class<?>[] resolveTypeArguments(java.lang.Class<?> clazz,
                                        java.lang.Class<?> genericIfc)

Resolve the type arguments of the given generic interface against the given target class which is assumed to implement the generic interface and possibly declare concrete types for its type variables.

Parameters:

clazz - the target class to check against

genericIfc - the generic interface or superclass to resolve the type argument from

Returns:

the resolved type of each argument, with the array size matching the number of actual type arguments, or null if not resolvable

resolveType

public static java.lang.Class<?> resolveType(java.lang.reflect.Type genericType,
                             java.util.Map<java.lang.reflect.TypeVariable<?>,java.lang.reflect.Type> typeVariableMap)

Resolve the specified generic type against the given TypeVariable map.

Parameters:

genericType - the generic type to resolve

typeVariableMap - the TypeVariable Map to resolved against

Returns:

the type if it resolves to a Class, or Object.class otherwise

getTypeVariableMap

public static java.util.Map<java.lang.reflect.TypeVariable<?>,java.lang.reflect.Type> getTypeVariableMap(java.lang.Class<?> clazz)

Build a mapping of TypeVariable names to concrete Class for the specified Class. Searches all super types, enclosing types and interfaces.