Why do I get an error 'No constructor with matching signature found.' when construct a Java object that has been added to javaclasspath?

I have a Java class with the following signatures:

package com.mathworks;

public class Test {

    Test() {

        System.out.println("Hello World!");

    }

}

I have used the 'javaaddpath' properly to load the class into MATLAB. However, when I try to construct an object:

>> com.mathworks.Test();

I got the following error:

No constructor 'com.mathworks.Test' with matching signature found.

Answer 1

[MathWorks Support Team]

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!");

    }

}