To prepare for a Java job, especially for roles like software developer, Java developer, or backend engineer, it’s essential to have a solid understanding of various topics. Here’s a comprehensive list of main topics you should study:
1. Core Java Concepts
Syntax and Basics: Variables, data types, operators, control flow statements (if-else, loops).
Object-Oriented Programming (OOP): Classes, objects, inheritance, polymorphism, abstraction, encapsulation, interfaces.
Exception Handling: Try-catch blocks, finally, throw and throws, custom exceptions.
Collections Framework: List, Set, Map, and their implementations like ArrayList, HashSet, HashMap.
Concurrency: Threads, synchronization, concurrency utilities (Executors, Future, CountDownLatch, etc.).
Java I/O: Streams, readers and writers, serialization.
Java 8+ Features: Lambda expressions, Stream API, Optional, new date and time API.
2. Advanced Java
Java Generics: Generic classes, methods, and wildcard usage.
Design Patterns: Singleton, Factory, Observer, Decorator, etc.
Annotations and Reflection: Custom annotations, using reflection for inspecting classes and methods.
Java Memory Model and Garbage Collection: Understanding memory management, GC algorithms, heap vs stack.
3. Web Technologies
Servlets and JSP: Basics of web applications, request-response cycle, session management.
RESTful Web Services: Designing REST APIs, using frameworks like Spring Boot, understanding JSON and XML.
Web Frameworks: Familiarity with Spring MVC, Spring Boot, or other frameworks used in web development.