100+ Java Exercises (Simple, Intermediate & Complex)

100+ Java Exercises (Simple, Intermediate & Complex) free download

Level Up Your Java Skills with Targeted Exercises – Master the Power of Java in This Ultimate Mega Pack!

This course takes you on a journey from foundational Java programming to expert-level skills, equipping you to design efficient, scalable, and maintainable software. Through hands-on exercises, real-world scenarios, and best practices, you’ll gain practical expertise in:

Java Core Concepts

1. Object-Oriented Programming (OOP)

   • Classes, objects, and constructors.

   • Method overriding and overloading.

   • Inheritance, polymorphism, and encapsulation.

   • Abstract classes and interfaces.

2. Generics

   • Implementing generic data structures (e.g., LockFreeStack<T>).

   • Using bounded type parameters.

3. Collections Framework

   • Using HashMap, LinkedHashMap, ConcurrentHashMap, Queue, and List.

   • Working with thread-safe collections.

4. Exception Handling

   • Handling checked and unchecked exceptions (IOException, InterruptedException, RuntimeException).

   • Using try-catch-finally and custom exception messages.

Concurrency and Multithreading

1. Thread Safety

   • Synchronization with synchronized blocks and methods.

   • Thread-safe data structures like AtomicReference and ConcurrentHashMap.

2. Advanced Concurrency Mechanisms

   • Non-blocking algorithms (e.g., LockFreeStack with Compare-And-Swap).

   • Blocking queues with wait() and notifyAll().

3. Executor Framework

   • Using ExecutorService, ScheduledExecutorService, and thread pools.

   • Task scheduling with fixed-rate and fixed-delay jobs.

4. Volatile and Atomicity

   • volatile for visibility across threads.

   • Atomic operations with AtomicInteger and compareAndSet.

5. Double-Checked Locking

   • Implementing thread-safe singletons with minimal synchronization overhead.

Data Structures and Algorithms

1. Custom Data Structures

   • LRU Cache using LinkedHashMap.

   • Lock-free stack with CAS.

   • Thread-safe bounded blocking queues.

2. Algorithmic Patterns

   • Implementing Least Recently Used (LRU) cache eviction.

   • Designing memory-efficient and high-performance ID generators (Snowflake-inspired).

Advanced Design Patterns

1. Singleton

   • Thread-safe Singleton with lazy initialization and double-checked locking.

2. Publish-Subscribe (Pub/Sub)

   • Implementing a messaging system with topics and subscribers.

3. Dependency Injection (DI)

   • Lightweight DI container for automatic dependency resolution.

4. Event-Driven Architectures

   • Custom event loops for asynchronous task execution.

Distributed Systems

1. Distributed ID Generators

   • Time-ordered unique IDs using timestamp, machine ID, and sequence numbers.

2. Fault Tolerance

   • Implementing Circuit Breaker patterns to handle service failures gracefully.

Performance Optimization

1. Lazy Initialization

   • Optimizing resource creation to defer initialization until necessary.

2. Non-Blocking Synchronization

   • Using CAS for high-performance, lock-free data structures.

3. Rate Limiting

   • Token Bucket algorithm for throttling API requests.

I/O and Serialization

1. Custom Serialization Framework

   • Using reflection for object serialization and deserialization.

2. File Processing

   • Multi-threaded processing of large files with efficient chunking.

Testing and Debugging

1. Unit Testing

   • Writing JUnit 5 tests for validating implementation correctness.

   • Testing thread safety and concurrency.

2. Error Handling

   • Gracefully managing system errors and preventing cascading failures.

Real-World Applications

1. Scalable Caches

   • Designing LRU caches for performance-critical applications.

2. Distributed Systems

   • Unique ID generators for large-scale distributed applications.

   • Circuit breakers for microservices.

3. Task Scheduling

   • Implementing schedulers for periodic and delayed tasks.

4. Messaging Systems

   • Publish-Subscribe patterns for decoupled communication.

Key Skills Practiced

• Designing and implementing thread-safe systems.

• Understanding and applying advanced synchronization techniques.

• Building scalable, fault-tolerant, and performant solutions.

• Applying real-world design patterns and best practices.