ru.vyarus.java.generics.resolver.context

Class MethodGenericsContext

java.lang.Object

ru.vyarus.java.generics.resolver.context.GenericsContext

ru.vyarus.java.generics.resolver.context.MethodGenericsContext

public class MethodGenericsContext
extends GenericsContext

Method generics context. Additional context is required because method could contain it's own generics, for example:

 class A {
     <T> T method();
 }

Such generics are not known in type and as a result any operation on type with such generic will lead to unknown generic.

Also, context contains special methods for parameters and return type analysis.

Since:

26.06.2015

Field Summary

Fields inherited from class ru.vyarus.java.generics.resolver.context.GenericsContext

currentType, genericsInfo, typeGenerics

Constructor Summary

Constructors

Constructor and Description
MethodGenericsContext(GenericsInfo genericsInfo, java.lang.Class<?> type, java.lang.reflect.Method method)

Method Summary

Modifier and Type	Method and Description
protected java.util.Map<java.lang.String,java.lang.reflect.Type>	contextGenerics()
java.lang.reflect.Method	currentMethod()
java.util.Map<java.lang.String,java.lang.reflect.Type>	methodGenericsMap() class A<E> { <T, K extends E> K method(T arg); } class B extends A<Serializable> context.method(A.getMethod("method", Object.class)).methodGenericsMap() == ["T": Object.class, "K": Serializable.class] For method generics it's impossible to know actual type (available only in time of method call), so generics resolved as lower bound.
java.util.List<java.lang.reflect.Type>	methodGenericTypes() <T extends Serializable> T method();.
java.util.List<java.lang.Class<?>>	resolveParameters() Useful for introspection, to know exact parameter types.
java.lang.Class<?>	resolveReturnClass() Useful for introspection, to know exact return type of generified method.
java.lang.Class<?>	resolveReturnTypeGeneric() Shortcut for resolveReturnTypeGenerics() useful for single generic types or when just first generic required.
java.util.List<java.lang.Class<?>>	resolveReturnTypeGenerics() Useful for introspection, to know exact generic value.

Methods inherited from class ru.vyarus.java.generics.resolver.context.GenericsContext

currentClass, generic, generic, genericAsString, genericAsString, generics, genericsAsString, genericsMap, genericType, genericType, genericTypes, getGenericsInfo, method, resolveClass, resolveGenericOf, resolveGenericsOf, toStringType, type

Methods inherited from class java.lang.Object

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

Constructor Detail

MethodGenericsContext

public MethodGenericsContext(GenericsInfo genericsInfo,
                             java.lang.Class<?> type,
                             java.lang.reflect.Method method)

Method Detail

currentMethod

public java.lang.reflect.Method currentMethod()

Returns:

current context method

methodGenericTypes

public java.util.List<java.lang.reflect.Type> methodGenericTypes()

<T extends Serializable> T method();.

 context.method(B.getMethod('method')).methodGenericTypes() == [Class<Serializable>]

Returns:

current method generics types

methodGenericsMap

public java.util.Map<java.lang.String,java.lang.reflect.Type> methodGenericsMap()

 class A<E> {
     <T, K extends E> K method(T arg);
 }
 class B extends A<Serializable>

 context.method(A.getMethod("method", Object.class)).methodGenericsMap() ==
          ["T": Object.class, "K": Serializable.class]

For method generics it's impossible to know actual type (available only in time of method call), so generics resolved as lower bound.

Returns:

map of current method generics (runtime mapping of generic name to actual type)

resolveReturnClass

public java.lang.Class<?> resolveReturnClass()

Useful for introspection, to know exact return type of generified method.

 class A extends B<Long>;
 class B<T> {
     T doSmth();
 }

Resolving return type in type of root class: type(B.class).resolveReturnClass(B.class.getMethod("doSmth")) == Long.class

Returns:

resolved return class of method (generic resolved or, in case of simple class, returned as is)

See Also:

GenericsContext.resolveClass(java.lang.reflect.Type)

resolveParameters

public java.util.List<java.lang.Class<?>> resolveParameters()

Useful for introspection, to know exact parameter types.

 class A extends B<Long>;
 class B<T> {
     void doSmth(T a, Integer b);
 }

Resolving parameters in context of root class: type(B.class).resolveParameters(B.class.getMethod("doSmth", Object.class)) == [Long.class, Integer.class]

Returns:

resolved method parameters or empty list if method doesn't contain parameters

resolveReturnTypeGenerics

public java.util.List<java.lang.Class<?>> resolveReturnTypeGenerics()
                                                             throws NoGenericException

Useful for introspection, to know exact generic value.

 class A extends B<Long>;
 class B<T> {
     List<T> doSmth();
 }

Resolving parameters in context of root class: type(B.class).method(B.class.getMethod("doSmth")).resolveReturnTypeGenerics() == [Long.class]

Returns:

resolved generic class

Throws:

NoGenericException - if provided type does not contain generic (exception required to distinguish Object.class generic value from class which doesn't support generic

resolveReturnTypeGeneric

public java.lang.Class<?> resolveReturnTypeGeneric()
                                            throws NoGenericException

Shortcut for resolveReturnTypeGenerics() useful for single generic types or when just first generic required.

Returns:

first resolved generic

Throws:

NoGenericException - if provided type does not contain generic (exception required to distinguish Object.class generic value from class which doesn't support generic

contextGenerics

protected java.util.Map<java.lang.String,java.lang.reflect.Type> contextGenerics()

Specified by:

contextGenerics in class GenericsContext

Returns:

resolved generics mapping for current context