Getter and Setter is new things for me since I have experience in Python which all attribute in a Class can be invoked anytime. It’s different in Java which all data should be thread-safe and manipulation between data should be isolated and not interfere another process/task.
Btw, did i mean “encapsulation” here? Well, there are a lot of long debate about Getter/Setter whether is part of encapsulation or not. But from my own perspective, Getter/Setter is more likely integration and interfacing.
Imagine, we have a Class that provide calculation of Student behaviour. We have sub-routine/function inside this class for processing student name. This function called “firstname”. There is another class which want to use this firstname() to get the student name. Then, Getter/Setter is the player here. Getter/Setter will invoke method firstname() to be able use by another class.
Example code TestPerson.java:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | class Person { private String firstname = null; public void setFirstname(String firstname){ /* Imagine there a lot of calculation things here */ this.firstname = firstname; } public String getFirstname() { return firstname; } } public class TestPerson { public static void main(String args[]) { Person p = new Person(); p.setFirstname("Yodiaditya"); System.out.println(p.getFirstname()); } } |
You can running this code by:
1 | javac TestPerson.java && java TestPerson |
So, this is how Getter/Setter works in Java. You can put whatever data processing data inside a Class and make them accessible (interface) to another class which want to use.