Java Technologies Notes
Subject Overview
Java Technologies covers core Java programming fundamentals (classes, arrays, strings, inheritance, interfaces and packages), and moves into exception handling, multithreading, applets, AWT, servlets and JDBC — building toward complete web-connected Java applications. A 4-credit core theory paper.
Subject at a glance
4
Units
45
Topics
4
Credits
4
Infographics
Unit-wise Syllabus
4 units — open any unit for detailed topic-wise notes, diagrams and important exam questions
- Introduction to Java and its origin/features
- Java API
- variables
- literals
- primitive data types
- the String class
- operators
- decision-making and looping statements
- jump statements
byte / short
8 / 16 bits
byte b = 10;
int / long
32 / 64 bits
long n = 9000L;
float / double
32 / 64 bits
double d = 3.14;
char
16 bits (Unicode)
char c = 'A';
boolean
true or false
boolean ok = true;
Study guide
This unit introduces Java: its origin and features, the API, variables, literals, primitive types, the String class, operators, decisions, loops and jump statements. Write and run programs as you learn.
- OOP basics
- classes and objects
- modifiers
- passing arguments
- constructors and overloading
- static class members
- garbage collection
- arrays (single/multi-dimensional)
- string handling classes
- inheritance basics
- overriding
- polymorphism
- abstract and final classes
- packages and interfaces
Methods
Abstract and concrete
Abstract, default and static
Variables
Any
Constants only (public static final)
Inheritance
extends one class
implements many interfaces
Use
Shared base with common code
Common contract across unrelated classes
Study guide
You study classes, objects, modifiers, constructors, overloading, static members, garbage collection, arrays, strings, inheritance, overriding, polymorphism, abstract and final classes, packages and interfaces. Draw class diagrams for every program.
- Try/catch/finally blocks
- multiple and nested catch
- throw statement
- built-in exceptions
- the Java thread model
- thread priorities
- synchronization
- inter-thread communication
- suspending/resuming/stopping threads
- 1. New: Thread created
- 2. Runnable: start() called
- 3. Running: Scheduler picks it
- 4. Blocked or waiting: sleep(), wait(), I/O
- 5. Terminated: run() finishes
Study guide
You study exception handling (try, catch, finally, throw, built-in exceptions) and multithreading: the thread model, priorities, synchronisation and inter-thread communication. Understand why synchronisation prevents race conditions.
- Applet class and lifecycle
- graphics in applets
- event handling
- AWT window fundamentals
- frame windows
- graphics/color/fonts
- servlet lifecycle and API
- reading servlet parameters
- handling HTTP requests/responses
- cookies and session tracking
- JDBC database connectivity
- SQL queries
- retrieving and updating data
- 1Load and instantiate
- 2init()
Called once
- 3service()
Handles each request: doGet, doPost
- 4destroy()
Called before removal
Study guide
You study applets, AWT, event handling, servlets (lifecycle, parameters, requests, cookies and sessions) and JDBC with SQL queries and updates. Build a small servlet that reads from a database.
Why Java Technologies Matters
Java powers enterprise applications and Android, and Java developer roles are plentiful, making it a reliable career skill.
How to Prepare for Java Technologies
- Build a small web application using servlets and JDBC.
- Learn exception handling and multithreading in depth.
- Practise coding problems in Java regularly.
Java Technologies: Frequently Asked Questions
What is a servlet?
A servlet is a Java program that runs on a server to handle web requests and generate dynamic responses.