CS 349 Java Final Exam

These flashcards cover essential Java programming concepts and components relevant for the final exam.

Encapsulation

Hiding internal details and showing only functionalities.

Inheritance

Mechanism where one class acquires properties of another.

Polymorphism

Ability of an object to take on many forms.

Abstraction

Hiding complex implementation details and showing only essentials.

Method Overloading

Same method name but different parameters.

Method Overriding

Child class redefines a parent method with same signature.

Constructor Rules

No return type; name must match class.

Implementing an Interface

Use 'implements' keyword in class declaration.

UML Class Diagram

Top: Class Name; Middle: Fields; Bottom: Methods.

Native Apps

Built specifically for Android/iOS platforms.

Web Apps

Accessed through a browser, not installed.

Hybrid Apps

Combination of native and web technologies.

RelativeLayout

Widgets positioned relative to others using IDs.

FrameLayout

Stacks multiple views on top of each other.

Good Layout Practice

Minimize layout depth for better performance.

Android Modes

Design Mode, Code Mode, Split Mode.

onCreate() Method

Initializes activity; sets content view.

setContentView()

Loads XML layout into an activity.

MVC Pattern in Android

Model: Data, View: UI Layouts, Controller: Activity logic.

Activity Component

Screen with a user interface.

Service Component

Runs background operations with no UI.

Broadcast Receiver

Listens for system-wide broadcast messages.

Content Provider

Shares data between apps, e.g., contacts.

What are the four main OOP principles in Java?

Encapsulation, Inheritance, Polymorphism, and Abstraction

Which method is used for executing SELECT statements in Java?

executeQuery()

Which method is used for INSERT, UPDATE, DELETE SQL statements

executeUpdate()

What are the three steps in Java Event Handling?

1. Create Event Source

2. Create Event Listener

3. Register Listener with Source

Which method does ActionListener interface have?

actionPerformed(ActionEvent e)

How do you create a Button in Java?

Button b = new Button(""Click Me"");

How do you get text from a TextField in Java?

String text = tf.getText();

What is the syntax for inheriting a class in Java?

public class A extends C

How do you inherit a class and implement an interface in Java?

public class A extends C implements E

What does the @Override annotation indicate?

A method in a subclass is intended to override a method in its superclass

What are common methods inherited from Object class?

toString(), equals(), hashCode(), clone()

What is the purpose of interfaces in Java?

To define a contract that implementing classes must follow

What are the characteristics of fields in a Java interface?

All fields are public, static, and final

What are the characteristics of methods in a Java interface?

All methods are public and abstract by default

How is inheritance represented in UML diagrams?

Solid line with a hollow arrow pointing from child to parent

Why minimize layout hierarchy depth?

To improve performance

What does the Model do in MVC?

Manages data and business logic

What does the View do in MVC?

Displays UI via XML layouts

What does the Controller do in MVC?

Handles user input and updates model/view