org.springframework.expression.spel.support

Class ReflectionHelper

  • java.lang.Object
    • org.springframework.expression.spel.support.ReflectionHelper


  • public abstract 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.
    Since:
    3.0
    Author:
    Andy Clement, Juergen Hoeller
    • Constructor Detail

      • ReflectionHelper

        public ReflectionHelper()
    • Method Detail

      • convertAllArguments

        public static boolean 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 - a subsequent call to setupArgumentsForVarargsInvocation handles that.
        Parameters:
        converter - the converter to use for type conversions
        arguments - the arguments to convert to the requested parameter types
        method - 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 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 types.
        Parameters:
        requiredParameterTypes - the types of the parameters for the invocation
        args - the arguments to be setup ready for the invocation
        Returns:
        a repackaged array of arguments where any varargs setup has been done