Get hold of Foo[].class given Foo.class

Question

I have an object, c , of type Class (I get hold of the object in runtime so I can't tell in compile-time which class it represents.)

Suppose c represents the class Foo . I now want to get hold of a Class -instance which represents Foo[] .

How is this done best using the standard Java API?

Answer 1

According to http://tutorials.jenkov.com/java-reflection/arrays.html , one of the ways is:

Class arrayClass = java.lang.reflect.Array.newInstance(c, 0).getClass();

This looks like a cheat, but it's definitely cleaner than playing with the class names .

Answer 2

Here's an example of how to do this:

import java.lang.reflect.Array;
public class ReflectTest {
    public static void main(String[] args) {
        Foo c = new ReflectTest().new Foo();
        Foo[] foos = (Foo[]) Array.newInstance(c.getClass(), 5);
    }
    class Foo {
    }
}

Answer 3

From what I can see in my test, this should work:

Class c = ...
Class cArr = java.lang.reflect.Array.newInstance(c, 1).getClass();