LocalDate hasn't constructor... How can we create classes without constructor?

Question

I'm reviewing Java 8 classes of the Time package and I have a doubt about the classes without constructor like LocalDate class.

If you create a Java class, this class will always have a default constructor, nevertheless LocalDate hasn't constructor, that is to say, you can't do this:

LocalDate date = new LocalDate();

If you do this, you will get a compile error "the constructor LocalDate() is undefined".

Why LocalDate hasn't a default constructor?

And the most important question... How can I create a class without constructor that only can be instanced calling static methods?

Thank you very much and regards.

Answer 1

Use

LocalDate d = LocalDate.now(); 

to create a LocalDate for now. There are more static methods to instantiate a LocalDate. The designers of the API decided to create static methods to instantiate LocalDates because they can have more clear names on what is actually instantiated (like "now()" above to create a LocalDate for the current date).

Answer 2

The typical pattern here is a class with only private or package default constructors, combined with a factory method that is either a public static method of the class or a method of an accompanying factory class. You get LocalDate objects from many static methods listed in the javadoc.