Invoke method with an Object List

Question

This code allow me invoking a method with tests parameter

Method m = aClass.getDeclaredMethod(methodName, paramTypes);
Integer n =10;
Object retobj =m.invoke(o, "test",n);
System.out.println(retobj);

Now I want to invoke the method with the arguments list.

List<Object> arguments =container.getArgs();
Object retobj =m.invoke(o, (Object) arguments);

But I get this error

java.lang.IllegalArgumentException: wrong number of arguments

Answer 1

The invoke method takes two parameters: the object on which to invoke the method, and a "varargs" parameter to hold the arguments.

Such a parameter (also "variable arity") is interchangeable with an array, and it's treated as an array in the body of such a method.

Convert your List<Object> to an array, then pass it in.

Object retobj = m.invoke(o, arguments.toArray());

Answer 2

在第一次invoke ，您传递了2个参数，在第二次invoke ，您仅传递了1个。