What is the best way to implement constants in Java?

That's the best way. (public/private) static final TYPE NAME = VALUE; In this way, TYPE refers to the type of variable, and NAME usually consists of uppercase letters and _. For VALUE, you can put a constant value.

Note that a variable cannot change its value if it is declared final, but for an object it cannot point to another object. For example,

public static final Point ORIGIN = new Point(0,0);

public static void main(String[] args){

    ORIGIN.x = 3;

}

In this case, ORIGIN.x=3 works normally and the value of the point is (3,0).