org.springframework.expression.spel.support
Class ReflectiveMethodResolver

java.lang.Object
  org.springframework.expression.spel.support.ReflectiveMethodResolver

All Implemented Interfaces:

MethodResolver

public class ReflectiveMethodResolver
extends java.lang.Object
implements MethodResolver

A method resolver that uses reflection to locate the method that should be invoked.

Since:

3.0

Author:

Andy Clement, Juergen Hoeller

Field Summary

private java.util.Map<java.lang.Class<?>,MethodFilter>	filters
private static java.lang.reflect.Method[]	NO_METHODS
private boolean	useDistance

Constructor Summary

ReflectiveMethodResolver()

ReflectiveMethodResolver(boolean useDistance)
This constructors allows the ReflectiveMethodResolver to be configured such that it will use a distance computation to check which is the better of two close matches (when there are multiple matches).

Method Summary

void	registerMethodFilter(java.lang.Class<?> type, MethodFilter filter)
MethodExecutor	resolve(EvaluationContext context, java.lang.Object targetObject, java.lang.String name, java.util.List<TypeDescriptor> argumentTypes) Locate a method on a type.

Methods inherited from class java.lang.Object

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

Field Detail

NO_METHODS

private static java.lang.reflect.Method[] NO_METHODS

filters

private java.util.Map<java.lang.Class<?>,MethodFilter> filters

useDistance

private boolean useDistance

Constructor Detail

ReflectiveMethodResolver

public ReflectiveMethodResolver()

ReflectiveMethodResolver

public ReflectiveMethodResolver(boolean useDistance)

This constructors allows the ReflectiveMethodResolver to be configured such that it will use a distance computation to check which is the better of two close matches (when there are multiple matches). Using the distance computation is intended to ensure matches are more closely representative of what a Java compiler would do when taking into account boxing/unboxing and whether the method candidates are declared to handle a supertype of the type (of the argument) being passed in.

Parameters:

useDistance - true if distance computation should be used when calculating matches

Method Detail

resolve

public MethodExecutor resolve(EvaluationContext context,
                              java.lang.Object targetObject,
                              java.lang.String name,
                              java.util.List<TypeDescriptor> argumentTypes)
                       throws AccessException

Locate a method on a type. There are three kinds of match that might occur:

1. An exact match where the types of the arguments match the types of the constructor
2. An in-exact match where the types we are looking for are subtypes of those defined on the constructor
3. A match where we are able to convert the arguments into those expected by the constructor, according to the registered type converter.

Specified by:

resolve in interface MethodResolver

Parameters:

context - the current evaluation context

targetObject - the object upon which the method is being called

argumentTypes - the arguments that the constructor must be able to handle

Returns:

a MethodExecutor that can invoke the method, or null if the method cannot be found

Throws:

AccessException

registerMethodFilter

public void registerMethodFilter(java.lang.Class<?> type,
                                 MethodFilter filter)