org.springframework.core

Class MethodIntrospector

java.lang.Object

org.springframework.core.MethodIntrospector

public final class MethodIntrospector
extends Object

Defines the algorithm for searching for metadata-associated methods exhaustively including interfaces and parent classes while also dealing with parameterized methods as well as common scenarios encountered with interface and class-based proxies.

Typically, but not necessarily, used for finding annotated handler methods.

Since:

4.2.3

Author:

Juergen Hoeller, Rossen Stoyanchev

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	MethodIntrospector.MetadataLookup<T> A callback interface for metadata lookup on a given method.

Method Summary

Modifier and Type	Method and Description
static Method	selectInvocableMethod(Method method, Class<?> targetType) Select an invocable method on the target type: either the given method itself if actually exposed on the target type, or otherwise a corresponding method on one of the target type's interfaces or on the target type itself.
static <T> Map<Method,T>	selectMethods(Class<?> targetType, MethodIntrospector.MetadataLookup<T> metadataLookup) Select methods on the given target type based on the lookup of associated metadata.
static Set<Method>	selectMethods(Class<?> targetType, ReflectionUtils.MethodFilter methodFilter) Select methods on the given target type based on a filter.

Methods inherited from class java.lang.Object

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

Method Detail

selectMethods

public static <T> Map<Method,T> selectMethods(Class<?> targetType,
                                              MethodIntrospector.MetadataLookup<T> metadataLookup)

Select methods on the given target type based on the lookup of associated metadata.

Callers define methods of interest through the MethodIntrospector.MetadataLookup parameter, allowing to collect the associated metadata into the result map.

Parameters:

targetType - the target type to search methods on

metadataLookup - a MethodIntrospector.MetadataLookup callback to inspect methods of interest, returning non-null metadata to be associated with a given method if there is a match, or null for no match

Returns:

the selected methods associated with their metadata (in the order of retrieval), or an empty map in case of no match

selectMethods

public static Set<Method> selectMethods(Class<?> targetType,
                                        ReflectionUtils.MethodFilter methodFilter)

Select methods on the given target type based on a filter.

Callers define methods of interest through the MethodFilter parameter.

Parameters:

targetType - the target type to search methods on

methodFilter - a MethodFilter to help recognize handler methods of interest

Returns:

the selected methods, or an empty set in case of no match

selectInvocableMethod

public static Method selectInvocableMethod(Method method,
                                           Class<?> targetType)

Select an invocable method on the target type: either the given method itself if actually exposed on the target type, or otherwise a corresponding method on one of the target type's interfaces or on the target type itself.

Matches on user-declared interfaces will be preferred since they are likely to contain relevant metadata that corresponds to the method on the target class.

Parameters:

method - the method to check

targetType - the target type to search methods on (typically an interface-based JDK proxy)

Returns:

a corresponding invocable method on the target type

Throws:

IllegalStateException - if the given method is not invocable on the given target type (typically due to a proxy mismatch)