java - Wrong number of arguments error when invoking a method

Question

I have class AClass and a method someMethod that gets an Object array as parameter.

public class AClass {
    public void someMethod(Object[] parameters) {
    }
}

In main, when I try to invoke this method on the the object that I have created and give an object array as a parameter to this method

Object[] parameters; // lets say this object array is null
Class class = Class.forName("AClass");
Object anObject = class.newInstance();

Method someMethod = class.getDeclaredMethod("someMethod", parameters.getClass());
someMethod.invoke(anObject, parameters);

I get "wrong number of arguments error". What am i missing?

Answer 1

That will be all right.

Object[] parameters = {new Object()}; // lets say this object array is null
Class clas = Class.forName("AClass");
Object anObject = clas.newInstance();

Object[] param = {parameters};

Method someMethod = clas.getDeclaredMethod("someMethod", parameters.getClass());
someMethod.invoke(anObject, param);

Be careful about the second parameter of the invoke method. It's Object[] itself, and the argument type of your method is Object[] too.