Java concurrency patterns are essential for building efficient, scalable, and thread-safe applications. Below are some core patterns and their use cases:

1. Producer-Consumer Pattern 📦

This pattern decouples data production and consumption using queues.

  • Use Case: Thread-safe data transfer between producers and consumers.
  • Implementation: Use BlockingQueue (e.g., LinkedBlockingQueue) to manage synchronization.
  • Example: 
    BlockingQueue<String> queue = new LinkedBlockingQueue<>();
// Producer
queue.put("data");
// Consumer
String item = queue.take();
Producer_Consumer

2. Thread Pool Pattern ⚙️

Reuses a fixed number of threads to execute tasks, reducing overhead.

  • Benefits:
    • Efficient resource management.
    • Prevents thread explosion.
  • Key Class: ExecutorService (e.g., Executors.newFixedThreadPool(4)).
  • Tip: Always shutdown the pool gracefully after use.

3. Singleton Pattern 🌟

Ensures a single instance of a class is shared across the application.

  • Thread-Safe Variant: 
    public class Singleton {  
    private static volatile Singleton instance;  
    public static Singleton getInstance() {  
        if (instance == null) {  
            synchronized (Singleton.class) {  
                if (instance == null) {  
                    instance = new Singleton();  
                }  
            }  
        }  
        return instance;  
    }  
}
Singleton_Pattern

4. Deadlock Avoidance ⚠️

Avoid situations where threads wait indefinitely for resources.

  • Strategy: Use ReentrantLock with timeouts or prioritize resource acquisition.
  • Tool: java.util.concurrent.locks.Lock for fine-grained control.

5. Read-Writers Lock 📖

Allows concurrent reads while writing is exclusive.

  • Use Case: High-read, low-write scenarios (e.g., configuration caching).
  • Java Class: ReentrantReadWriteLock from java.util.concurrent.locks.

For deeper insights into Java concurrency, explore our guide on Thread Safety Tips. 🚀

Note: All images are placeholders and may not reflect actual content.