static and final Keywords in Java: Variables, Methods, Blocks and Classes

static and final are two of the most used Java modifiers. static makes a member belong to the class instead of each object; final stops a variable, method or class from being changed. Together they give you constants such as static final int TIMEOUT = 10.

static Keyword

public class Counter {
    // static field: SHARED across ALL instances
    private static int count = 0;
    private int id;

    public Counter() {
        count++;   // shared counter increments
        id = count;// each object gets unique id
    }

    // static method: called on class, not object
    public static int getCount() {
        return count;
        // Cannot use 'this' or access instance fields!
    }

    // static block: runs once when class is loaded
    static {
        System.out.println("Counter class loaded!");
    }

    // static nested class
    public static class Helper {
        public void help() { System.out.println("Helping!"); }
    }
}

Counter.getCount();   // 0 — called on class
new Counter();
new Counter();
Counter.getCount();   // 2 — shared across instances

final Keyword

// 1. final VARIABLE: cannot be reassigned
final int MAX = 100;
// MAX = 200;  // COMPILE ERROR

// 2. final REFERENCE: reference cannot change, object CAN
final List<String> list = new ArrayList<>();
list.add("Java");  // OK! Modifying object
// list = new ArrayList<>();  // COMPILE ERROR: can't reassign ref

// 3. final FIELD: must be assigned in constructor or declaration
public class Employee {
    final String employeeId;  // must be set in constructor
    public Employee(String id) {
        this.employeeId = id;  // only place to set final field
    }
}

// 4. final METHOD: cannot be overridden
public class Parent {
    public final void template() { /* cannot override */ }
}

// 5. final CLASS: cannot be extended (e.g. String, Integer)
public final class Immutable { }
// class Child extends Immutable { }  // COMPILE ERROR

Interview Questions

Can we override a static method?

No. Static methods are class-level, not object-level. What looks like overriding is 'method hiding' — the child class's version hides the parent's. No dynamic dispatch — which version runs depends on the REFERENCE type, not the object type.

What is the difference between final, finally, and finalize?

final: keyword for variables/methods/classes. finally: block in try-catch that always executes. finalize(): method called by GC before object is collected (deprecated since Java 9 and marked for removal since Java 18).

static and final Together: Constants

public final class Config {
    public static final int DEFAULT_TIMEOUT_SECONDS = 10;      // one shared, unchangeable value
    public static final String BASE_URL = System.getProperty("baseUrl", "https://qa.example.com");

    private Config() { }                                       // no instances: utility class
}

Constants are static final, named in UPPER_SNAKE_CASE, and grouped in a class that can't be instantiated or extended.

Where You Use Them in a Test Framework

The one thing not to make plain static is the WebDriver itself: a single static driver is shared by every thread, which breaks parallel runs.