The current EL implementation does not consider the method parameter types and selects functions based on the number of method paramters. This leds to the problem that Spin can not use method overloading with the same number of parameters.
Decide whether this can be fixed in the engine or all Spin methods names has to be unique considering the number of parameters.
Related Issue for JUEL:
https://github.com/beckchr/juel/issues/72
BeanELResolver#invoke [1] can be provided with an array of Class objects that are the parameter types of the method to invoke. However, methods must match these types exactly.
[1] http://docs.oracle.com/javaee/6/api/javax/el/BeanELResolver.html#invoke%28javax.el.ELContext,%20java.lang.Object,%20java.lang.Object,%20java.lang.Class[],%20java.lang.Object[]%29