10 modules
Java tutorial for beginners: learn Java step by step
This Java tutorial takes you from your first program to building and testing a real application. It is organised into 10 modules that follow the order most people learn Java in: setting up the JDK and writing your first class, then variables, control flow, methods and arrays, object-oriented programming, exceptions, collections and generics, lambdas and streams, files, threads and databases with JDBC, and finally unit testing with JUnit 5 and a capstone project.
Who this Java course is for
It is written for students who are new to programming or new to Java, and for anyone preparing for placement interviews where Java is the language of choice. Each module builds on the previous one, so you can start at module 1 with no prior experience. If you already know the basics, jump straight to object-oriented programming, collections or streams, the areas interviewers ask about most.
How to get the most out of it
Type the examples instead of copying them, run them in the Webhise online compiler, and change one thing at a time to see what happens. After each module, explain its main idea out loud as if you were in an interview. The capstone at the end, an enrolment tracker you design, build and test, ties every module together into something you can talk about on your resume.
Course outline
Module 1. Getting Started with Java
What Java is, how to install the JDK, the structure of a Java program, how code is compiled and run, printing output, and writing readable code.
Module 2. Java Basics
Variables, data types, type conversion and casting, operators and expressions, and reading user input with Scanner.
Module 3. Control Flow
Making decisions with if/else and switch, and repeating work with while, do-while and for loops, nested loops, break and continue.
Module 4. Methods, Arrays and Strings
Writing reusable methods with parameters and return values, method overloading, arrays, String methods and StringBuilder.
Module 5. Object-Oriented Programming
Classes and objects, constructors and this, encapsulation with getters and setters, inheritance, polymorphism, and abstraction with abstract classes and interfaces.
Module 6. Exception Handling
Handling errors with try, catch and finally; checked vs unchecked exceptions; throw and throws; custom exceptions; and try-with-resources.
Module 7. Collections and Generics
ArrayList and the List interface, sets, maps, iterating and sorting with Comparator, and writing type-safe generic classes and methods.
Module 8. Lambdas and Streams
Lambda expressions, functional interfaces, method references, the Stream API, collectors and Optional.
Module 9. Files, Concurrency and JDBC
Reading and writing files with java.nio.file, threads and ExecutorService, synchronization basics, and database access with JDBC, PreparedStatement and transactions.
Module 10. Testing, Debugging and Capstone
Unit testing with JUnit 5, writing good tests, debugging and reading stack traces, and a two-part capstone: designing, building and testing an enrolment tracker.
Frequently asked questions
- Is Java good for beginners?
- Yes. Java has a clear, strict syntax and strong typing, so mistakes are caught early by the compiler. It is also widely used in placement tests, enterprise software and Android, which makes it a practical first language.
- What do I need to start learning Java?
- A Java Development Kit (JDK) to compile and run programs, or simply a browser: you can run every example in the Webhise online compiler without installing anything.
- What does this Java tutorial cover?
- Ten modules: getting started, Java basics, control flow, methods, arrays and strings, object-oriented programming, exception handling, collections and generics, lambdas and streams, files, concurrency and JDBC, and testing with JUnit 5 plus a capstone project.
- Which Java topics matter most for interviews?
- Object-oriented programming (inheritance, polymorphism, abstraction, interfaces), strings, collections such as ArrayList and HashMap, exception handling, and Java 8 features like lambdas and streams.
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