Java Full Stack Developer Path
An end-to-end guide covering frontend, backend, databases, and deployment.
1. Introduction to Java
Java is a high-level, class-based, object-oriented programming language designed to have as few implementation dependencies as possible. Developed by James Gosling at Sun Microsystems and released in 1995, it has become one of the most popular programming languages in the world.
The core principle of Java is "Write Once, Run Anywhere" (WORA), which means that compiled Java code can run on all platforms that support Java without the need for recompilation.
public class HelloWorld {\n public static void main(String[] args) {\n System.out.println("Hello, World!");\n }\n}2. JVM, JRE, and JDK Explained
Understanding the Java environment is crucial. The JDK (Java Development Kit) is for developers, containing the JRE and tools. The JRE (Java Runtime Environment) is for running Java apps, containing the JVM. The JVM (Java Virtual Machine) executes the bytecode, making Java platform-independent.
3. Variables & Data Types
Variables are containers for data. Java is statically-typed, so you must declare a variable's type. Primitive types include `int`, `double`, `char`, and `boolean`. Reference types refer to objects like `String`.
4. Operators
Operators perform actions on variables. Main types include Arithmetic (`+`, `-`), Comparison (`==`, `>`), and Logical (`&&`, `||`).
5. Control Flow Statements
Control the execution path of your code. Use `if-else` for decisions, `for` and `while` for loops, and `switch` for multiple conditions.
6. OOPs Concepts
Object-Oriented Programming is a paradigm based on objects. The four pillars are Encapsulation, Abstraction, Inheritance, and Polymorphism.
7. Classes and Objects
A class is a blueprint for creating objects. An object is an instance of a class. A class defines attributes (state) and methods (behavior).
8. Constructors
A constructor is a special method for initializing a new object. It has the same name as the class and no return type.
9. Inheritance
Inheritance allows a new class (subclass) to acquire properties from an existing class (superclass) using the `extends` keyword, promoting code reuse.
10. Polymorphism
Meaning "many forms," it allows an object to be treated as an instance of its parent class. It's achieved through method overriding (runtime) and overloading (compile-time).
1. Advanced Collections
Explore specialized collections like `LinkedHashMap` for insertion order, `TreeSet` for sorted sets, and `ConcurrentHashMap` for thread-safe operations.
2. Multithreading
Learn to run multiple parts of a program concurrently by extending the `Thread` class or implementing the `Runnable` interface. Key concepts include synchronization and thread pools.
3. JDBC
Java Database Connectivity (JDBC) is the API for connecting Java applications to databases. Learn to use `Connection`, `Statement`, and `ResultSet` to execute SQL queries.
4. Generics
Generics add compile-time type safety to your collections. Using types as
parameters (e.g., `List
5. Exception Handling
Master the use of `try-catch-finally` blocks to create resilient applications. Understand the difference between checked and unchecked exceptions and how to create custom exceptions.
6. File I/O & Serialization
Learn to read from and write to files using Java's I/O streams. Serialization is the process of converting an object's state into a byte stream to be stored or transmitted.
7. Lambda Expressions
Introduced in Java 8, lambdas provide a concise syntax for implementing functional interfaces (interfaces with a single abstract method), enabling a more functional programming style.
8. Stream API
The Stream API provides a powerful, declarative way to process sequences of elements. Learn to use intermediate (`filter`, `map`) and terminal (`collect`, `forEach`) operations for efficient data manipulation.
9. Networking
Explore Java's networking capabilities with the `java.net` package. Learn to build client-server applications using `Socket` and `ServerSocket` for TCP communication.
10. Annotations
Annotations provide metadata about your code. They are heavily used by frameworks like Spring (`@Component`, `@Autowired`) and JPA (`@Entity`) for configuration and behavior modification.
1. HTML5
HTML is the backbone of the web. Learn to structure your web pages using semantic
HTML5 elements like `
2. CSS3 & Flexbox
CSS styles your HTML. Learn modern layout techniques with Flexbox, a powerful model for aligning and distributing items in a container, essential for responsive design.
3. Bootstrap
Bootstrap is a CSS framework that accelerates development. Learn its responsive grid system (`row`, `col-`) and pre-built components like navbars, cards, and modals.
4. JavaScript Basics
Learn the core language of web interactivity: variables (`let`, `const`), data types, functions, and control flow (`if`, `for`).
5. DOM Manipulation
The Document Object Model (DOM) is how JavaScript interacts with HTML. Learn to select elements, change their content and styles, and respond to user events like clicks.
6. ES6+ Features
Modernize your JavaScript with ES6 features like arrow functions, template literals, destructuring, and the spread/rest operators for cleaner and more powerful code.
7. APIs & Fetch
Learn how to make asynchronous network requests to server-side APIs using the modern `fetch()` API, which uses Promises to handle responses from the server.
8. Introduction to React
React is a library for building user interfaces with components. Understand its declarative nature, the concept of a Virtual DOM, and how it efficiently updates the UI.
9. React Components & Props
Components are the reusable building blocks of a React app. Learn how to create them and pass data from parent to child components using `props`.
10. React State & Hooks
Manage dynamic data within your components using `state`. Learn the `useState` hook to add state to functional components and `useEffect` to handle side effects.
1. Introduction to SQL
SQL (Structured Query Language) is the standard language for relational databases. Learn its purpose and basic syntax for querying data.
2. MySQL Setup
MySQL is a popular open-source RDBMS. This covers installing the server and using a client like MySQL Workbench to connect and create your first database.
3. DDL & DML Commands
Learn the difference between Data Definition Language (`CREATE`, `ALTER`, `DROP`) for schema and Data Manipulation Language (`INSERT`, `UPDATE`, `DELETE`) for data.
4. The SELECT Statement
Master the `SELECT` statement, the workhorse of SQL. Learn to use `FROM`, `WHERE`, and `ORDER BY` to retrieve and sort data precisely.
5. SQL Joins
Combine data from multiple tables using `JOIN`. Understand the difference between `INNER JOIN`, `LEFT JOIN`, `RIGHT JOIN`, and `FULL OUTER JOIN`.
6. Aggregate Functions
Perform calculations on sets of data using functions like `COUNT()`, `SUM()`, `AVG()`, `MIN()`, and `MAX()`, often paired with the `GROUP BY` clause.
7. Subqueries
A subquery is a query nested inside another. Learn how to use them to perform complex, multi-step data retrieval operations.
8. Indexes
Indexes are crucial for database performance. Learn how they work, how to create them, and how they speed up data retrieval at the cost of slower writes.
9. Normalization
Normalization is the process of organizing tables to reduce data redundancy and improve data integrity. Understand the first three normal forms (1NF, 2NF, 3NF).
10. Transactions & ACID
A transaction ensures that a group of SQL statements executes completely or not at all. Learn about the ACID properties (Atomicity, Consistency, Isolation, Durability) that guarantee reliability.
1. Introduction to Servlets
Servlets are Java programs that run on a web server, acting as a middle layer between a request from a browser and a database or other applications.
2. Servlet Lifecycle
A servlet's life is managed by the container. It follows three key phases: initialization (`init()`), servicing requests (`service()`), and destruction (`destroy()`).
3. HttpServletRequest
Learn to use the `HttpServletRequest` object to access incoming HTTP data, including parameters, headers, and cookies.
4. HttpServletResponse
The `HttpServletResponse` object is used to send a response back to the client. Learn to set the content type, status codes, and write HTML back to the browser.
5. Session Management
Since HTTP is stateless, learn how to track users across multiple requests using the `HttpSession` API, a fundamental part of building web applications.
7. Filters & Listeners
Filters intercept requests and responses, allowing you to perform tasks like logging or authentication. Listeners respond to lifecycle events in the web application.
8. Introduction to JSP
JavaServer Pages (JSP) is a technology for creating dynamic web pages. It allows you to embed Java code into your HTML, making it easier to generate the view layer.
9. JSP Action Tags
Action tags are XML-based tags that control the flow of the JSP page. Learn to
use tags like `
10. JSTL
The JSP Standard Tag Library (JSTL) provides a set of standard tags that replace the need for messy Java scriptlets, allowing for cleaner loops, conditionals, and more.
1. Introduction to Spring Boot
Spring Boot simplifies Spring application development. Learn its core features: auto-configuration, starter dependencies, and the ability to create standalone applications.
2. Dependency Injection (DI)
Dependency Injection is a core concept in Spring. Understand how the IoC (Inversion of Control) container manages your objects (Beans) and injects their dependencies automatically.
3. Building REST APIs
Learn to build RESTful web services with Spring Boot using annotations like `@RestController`, `@GetMapping`, and `@PostMapping` to handle HTTP requests.
4. Spring Data JPA
Spring Data JPA makes database interaction incredibly simple. Learn how to create a repository interface that automatically provides full CRUD functionality for your entities.
5. Spring MVC
Learn the Model-View-Controller pattern in Spring for building web applications. Understand the flow of a request from the `DispatcherServlet` to a `@Controller`.
6. Spring Security
Secure your application with Spring Security. This covers basic authentication, authorization, and protection against common web vulnerabilities.
7. Validation
Use the Bean Validation API with annotations like `@NotNull` and `@Size` to automatically validate incoming request data and ensure data integrity.
8. Aspect-Oriented Programming (AOP)
AOP allows you to handle cross-cutting concerns like logging and security. Learn how to define Aspects, Pointcuts, and Advices to modularize this logic.
9. Testing with JUnit & Mockito
Learn to write unit and integration tests for your Spring Boot application using JUnit 5, `@SpringBootTest`, and Mockito to mock dependencies.
10. Actuator & Monitoring
Spring Boot Actuator provides production-ready features for monitoring your app. Learn to use its endpoints like `/health` and `/metrics` to keep an eye on your application's status.