1. I have an Interface in my project.

2. End users can implement this interface and can create their concrete implementations.

3. All the users have been advised to follow singleton design pattern while creating the implementations.

4. Users would store the implementations in a properties file.

5. I use Java Reflection to load the classes as shown below.

6. The above method has been very bad for the performance and hence I have decided to move the loading part to Java ServiceLoader instead for various reason.

7. But, ServiceLoader requires a public no-args constructor to load the classes which is quite a hurdle.

8. Is there a way to achieve the class loading using Java ServiceLoader with private constructor in place, or can I make the singleton implementations safe with a public no-args constructor.

I have read the documentation, and googled the probable solutions but found nothing substantial.

How classes are loaded now:

Class klass = Class.forName(klassName);
Method method = klass.getDeclaredMethod("getInstance");
Object object = method.invoke(null);

I just want to get rid of this, properties file and move on to Java ServiceLoader like I have moved for other classes which were not singletons.