How to pass a static class as an argument in Java

Question

I have a base class called "Entity" which has a static method called "construct" that returns an Entity instance. I have several different subclasses of this class (for demonstration assume we have "Fruit" and "Vegetable" as subclasses). I would like to be able to do something along the following lines:

Entity a = someFunction(Fruit, textfile)

someFunction would then pass textfile to Fruit.construct and return the Entity generated. Is there a simple way to do this?

Answer 1

You mean something like this:

public <T> T someFunction(Class<T> clazz, String textFile) throws Throwable {
 return clazz.newInstance();
}

The above code will use the no-arguments Constructor of the class (assuming there's one).

If your class needs to be instantiated with a specific constructor, you can do follow this example:

public <T> T someFunction(Class<T> clazz, String textFile) throws Throwable {
  // Here I am assuming the the clazz Class has a constructor that takes a String as argument.
  Constructor<T> constructor = clazz.getConstructor(new Class[]{String.class});
  T obj = constructor.newInstance(textFile);
  return obj;
}