Java reflection API: Invoking a method without parameters

Coding from the hip, it would be something like:

java.lang.reflect.Method method;
try {
  method = obj.getClass().getMethod(methodName, param1.class, param2.class, ..);
} catch (SecurityException e) { ... }
  catch (NoSuchMethodException e) { ... }

The parameters identify the very specific method you need (if there are several overloaded available, if the method has no arguments, only give methodName).

Then you invoke that method by calling

try {
  method.invoke(obj, arg1, arg2,...);
} catch (IllegalArgumentException e) { ... }
  catch (IllegalAccessException e) { ... }
  catch (InvocationTargetException e) { ... }

Again, leave out the arguments in .invoke, if you don't have any. But yeah. Read about Java Reflection

You need to use reflection to get the method to start with, then "construct" it by supplying type arguments with MakeGenericMethod:

MethodInfo method = typeof(Sample).GetMethod(nameof(Sample.GenericMethod));
MethodInfo generic = method.MakeGenericMethod(myType);
generic.Invoke(this, null);

For a static method, pass null as the first argument to Invoke. That's nothing to do with generic methods - it's just normal reflection.

As noted, a lot of this is simpler as of C# 4 using dynamic - if you can use type inference, of course. It doesn't help in cases where type inference isn't available, such as the exact example in the question.