Package org.apache.tapestry5.commons.services

Interface GenericsResolver

All Known Implementing Classes:

GenericsResolverImpl, GuavaGenericsResolver

public interface GenericsResolver

Methods related to the use of Java 5+ generics. Instances should be obtained through GenericsResolver.Provider.getInstance().

If you have exceptions or bad results with classes using Generics, such as exceptions or missing BeanModel properties, you should try adding the genericsresolver-guava Tapestry subproject to our classpath.

Since:

5.5.0

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	GenericsResolver.Provider	Convenience class for getting a GenericsResolver instance.

Method Summary

Modifier and Type	Method	Description
Class	asClass(Type actualType)	Get the class represented by the reflected type.
Type	extractActualType(Type containingType, Field field)	Analyzes the method in the context of containingClass and returns the Class that is represented by the method's generic return type.
Type	extractActualType(Type containingType, Method method)	Analyzes the method in the context of containingClass and returns the Class that is represented by the method's generic return type.
Class	extractGenericFieldType(Class containingClass, Field field)	Analyzes the field in the context of containingClass and returns the Class that is represented by the field's generic type.
Class<?>	extractGenericReturnType(Class<?> containingClass, Method method)	Analyzes the method in the context of containingClass and returns the Class that is represented by the method's generic return type.
Type	resolve(Type type, Type containingType)	Resolves the type parameter based on the context of the containingType.

Method Detail

extractGenericReturnType

Class<?> extractGenericReturnType(Class<?> containingClass,
                                  Method method)

Analyzes the method in the context of containingClass and returns the Class that is represented by the method's generic return type. Any parameter information in the generic return type is lost. If you want to preserve the type parameters of the return type consider using extractActualType(java.lang.reflect.Type, java.lang.reflect.Method).

Parameters:

containingClass - class which either contains or inherited the method

method - method from which to extract the return type

Returns:

the class represented by the methods generic return type, resolved based on the context .

See Also:

resolve(java.lang.reflect.Type,java.lang.reflect.Type), asClass(java.lang.reflect.Type)

extractGenericFieldType

Class extractGenericFieldType(Class containingClass,
                              Field field)

Analyzes the field in the context of containingClass and returns the Class that is represented by the field's generic type. Any parameter information in the generic type is lost, if you want to preserve the type parameters of the return type consider using #getTypeVariableIndex(java.lang.reflect.TypeVariable).

Parameters:

containingClass - class which either contains or inherited the field

field - field from which to extract the type

Returns:

the class represented by the field's generic type, resolved based on the containingClass.

See Also:

extractActualType(java.lang.reflect.Type, java.lang.reflect.Field), resolve(java.lang.reflect.Type,java.lang.reflect.Type), asClass(java.lang.reflect.Type)

extractActualType

Type extractActualType(Type containingType,
                       Method method)

Analyzes the method in the context of containingClass and returns the Class that is represented by the method's generic return type. Any parameter information in the generic return type is lost.

Parameters:

containingType - Type which is/represents the class that either contains or inherited the method

method - method from which to extract the generic return type

Returns:

the generic type represented by the methods generic return type, resolved based on the containingType.

See Also:

resolve(java.lang.reflect.Type,java.lang.reflect.Type)

extractActualType

Type extractActualType(Type containingType,
                       Field field)

Analyzes the method in the context of containingClass and returns the Class that is represented by the method's generic return type. Any parameter information in the generic return type is lost.

Parameters:

containingType - Type which is/represents the class that either contains or inherited the field

field - field from which to extract the generic return type

Returns:

the generic type represented by the methods generic return type, resolved based on the containingType.

See Also:

resolve(java.lang.reflect.Type,java.lang.reflect.Type)

resolve

Type resolve(Type type,
             Type containingType)

Resolves the type parameter based on the context of the containingType. TypeVariable will be unwrapped to the type argument resolved form the class hierarchy. This may be something other than a simple Class if the type argument is a ParameterizedType for instance (e.g. List<E>; List<Map<Long, String>>, E would be returned as a ParameterizedType with the raw type Map and type arguments Long and String.

Parameters:

type - the generic type (ParameterizedType, GenericArrayType, WildcardType, TypeVariable) to be resolved

containingType - the type which his

Returns:

the type resolved to the best of our ability.

asClass

Class asClass(Type actualType)

Get the class represented by the reflected type. This method is lossy; You cannot recover the type information from the class that is returned. TypeVariable the first bound is returned. If your type variable extends multiple interfaces that information is lost. WildcardType the first lower bound is returned. If the wildcard is defined with upper bounds then Object is returned.

Parameters:

actualType - a Class, ParameterizedType, GenericArrayType

Returns:

the un-parameterized class associated with the type.