Spring Framework

Class ReflectionHelper

  extended by org.springframework.expression.spel.support.ReflectionHelper

public class ReflectionHelper
extends java.lang.Object

Utility methods used by the reflection resolver code to discover the appropriate methods/constructors and fields that should be used in expressions.

Andy Clement, Juergen Hoeller

Nested Class Summary
static class ReflectionHelper.ArgsMatchKind
static class ReflectionHelper.ArgumentsMatchInfo
          An instance of ArgumentsMatchInfo describes what kind of match was achieved between two sets of arguments - the set that a method/constructor is expecting and the set that are being supplied at the point of invocation.
Constructor Summary
Method Summary
static void convertAllArguments(TypeConverter converter, java.lang.Object[] arguments, java.lang.reflect.Method method)
          Convert a supplied set of arguments into the requested types.
static int getTypeDifferenceWeight(java.util.List<TypeDescriptor> paramTypes, java.util.List<TypeDescriptor> argTypes)
          Based on MethodInvoker.getTypeDifferenceWeight(Class[], Object[]) but operates on TypeDescriptors.
static java.lang.Object[] setupArgumentsForVarargsInvocation(java.lang.Class[] requiredParameterTypes, java.lang.Object... args)
          Package up the arguments so that they correctly match what is expected in parameterTypes.
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail


public ReflectionHelper()
Method Detail


public static int getTypeDifferenceWeight(java.util.List<TypeDescriptor> paramTypes,
                                          java.util.List<TypeDescriptor> argTypes)
Based on MethodInvoker.getTypeDifferenceWeight(Class[], Object[]) but operates on TypeDescriptors.


public static void convertAllArguments(TypeConverter converter,
                                       java.lang.Object[] arguments,
                                       java.lang.reflect.Method method)
                                throws SpelEvaluationException
Convert a supplied set of arguments into the requested types. If the parameterTypes are related to a varargs method then the final entry in the parameterTypes array is going to be an array itself whose component type should be used as the conversion target for extraneous arguments. (For example, if the parameterTypes are {Integer, String[]} and the input arguments are {Integer, boolean, float} then both the boolean and float must be converted to strings). This method does not repackage the arguments into a form suitable for the varargs invocation

converter - the converter to use for type conversions
arguments - the arguments to convert to the requested parameter types
method - the target Method
SpelEvaluationException - if there is a problem with conversion


public static java.lang.Object[] setupArgumentsForVarargsInvocation(java.lang.Class[] requiredParameterTypes,
                                                                    java.lang.Object... args)
Package up the arguments so that they correctly match what is expected in parameterTypes. For example, if parameterTypes is (int, String[]) because the second parameter was declared String... then if arguments is [1,"a","b"] then it must be repackaged as [1,new String[]{"a","b"}] in order to match the expected parameterTypes.

requiredParameterTypes - the types of the parameters for the invocation
args - the arguments to be setup ready for the invocation
a repackaged array of arguments where any varargs setup has been done

Spring Framework