Why can't Java Reflection find the package-private constructor of a class in another package?

Question

I have the following API code, shortened for brevity:

public class Vec
{
    Vec(int x, int y, int z) {/*implementation*/}
    //other fields and methods irrelevant to question and not shown
}

Now, I'm trying to write code in a package different from that class above that uses reflection to invoke the constructor of that class and create a new instance of it. Here's what I've tried (code below is in my application's main method):

Constructor<Vec> c = Vec.class.getConstructor(Integer.TYPE, Integer.TYPE, Integer.TYPE);
c.setAccessible(true);
Vec newVec = c.newInstance(1, 2, 3);

However, when running the above code, I get an exception on the first line in the latter code:

Exception in thread "main" java.lang.NoSuchMethodException: somePackages.Vec.<init>(int, int, int)

Why is it still giving that exception, even if that constructor still exists? I'm running this code using oracle-java8-jdk on my Raspberry Pi, if that helps.

Answer 1

Class#getConstructor(Object...) javadoc states

Returns a Constructor object that reflects the specified public constructor of the class represented by this Class object

Your constructor is not public . It has no access modifier and is therefore package private.

Use getDeclaredConstructor(Object...) .