Constants can be defined using the final keyword, which means that the variable can be assigned at most once, either in the declaration itself, or with a static initializer method if the constant is defined in a class. This example declares two constants. The first is initialized in the declaration statement. The second is assigned a value in a static block by calling a static method.
public class myCls { static final Integer PRIVATE_INT_CONST = 200; static final Integer PRIVATE_INT_CONST2; public static Integer calculate() { return 2 + 7; } static { PRIVATE_INT_CONST2 = calculate(); } }
For more information, see Using the final Keyword.