The reason is that the Java class constructor is not defined with an access modifier. Hence by default it will be treated as 'protected'.
This means that only classes in the same package would be able to access the constructor of this class.
You can find more information on access modifiers on Oracles website:
https://docs.oracle.com/javase/tutorial/java/javaOO/accesscontrol.html
In order for MATLAB to construct an object of the class, please define the constructor as 'public' as the following:
package com.mathworks;
public class Test {
public Test() {
System.out.println("Hello World!");
}
}
