Class ReflectionHelper
- java.lang.Object
- org.springframework.expression.spel.support.ReflectionHelper
public class ReflectionHelper extends Object
Utility methods used by the reflection resolver code to discover the appropriate methods/constructors and fields that should be used in expressions.- Since:
- 3.0
- Author:
- Andy Clement, Juergen Hoeller
Constructor Summary
Constructors Constructor Description ReflectionHelper()
Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static boolean
convertAllArguments(TypeConverter converter, Object[] arguments, Method method)
Convert a supplied set of arguments into the requested types.static int
getTypeDifferenceWeight(List<TypeDescriptor> paramTypes, List<TypeDescriptor> argTypes)
Based onMethodInvoker.getTypeDifferenceWeight(Class[], Object[])
but operates on TypeDescriptors.static Object[]
setupArgumentsForVarargsInvocation(Class<?>[] requiredParameterTypes, Object... args)
Package up the arguments so that they correctly match what is expected in parameterTypes.
Constructor Detail
ReflectionHelper
public ReflectionHelper()
Method Detail
getTypeDifferenceWeight
public static int getTypeDifferenceWeight(List<TypeDescriptor> paramTypes, List<TypeDescriptor> argTypes)
Based onMethodInvoker.getTypeDifferenceWeight(Class[], Object[])
but operates on TypeDescriptors.
convertAllArguments
public static boolean convertAllArguments(TypeConverter converter, Object[] arguments, 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 - a subsequent call to setupArgumentsForVarargsInvocation handles that.- Parameters:
converter
- the converter to use for type conversionsarguments
- the arguments to convert to the requested parameter typesmethod
- the target Method- Returns:
- true if some kind of conversion occurred on the argument
- Throws:
SpelEvaluationException
- if there is a problem with conversion
setupArgumentsForVarargsInvocation
public static Object[] setupArgumentsForVarargsInvocation(Class<?>[] requiredParameterTypes, 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 declaredString...
, then if arguments is[1,"a","b"]
then it must be repackaged as[1,new String[]{"a","b"}]
in order to match the expected types.- Parameters:
requiredParameterTypes
- the types of the parameters for the invocationargs
- the arguments to be setup ready for the invocation- Returns:
- a repackaged array of arguments where any varargs setup has been done