Java Streams: Avoid ConcurrentModificationException

🚀 Java Tip Most Developers Learn Too Late Did you know this small mistake can silently hurt your application performance? List<User> users = new ArrayList<>(); users.stream() .filter(u -> u.isActive()) .forEach(u -> users.add(u)); // ❌ This throws a ConcurrentModificationException at runtime. ✅ The right approach: List<User> activeUsers = users.stream() .filter(User::isActive) .toList(); 🔍 Why this matters: Java Streams are not meant for modifying the source collection Side effects inside streams lead to unpredictable bugs Clean, functional-style code is easier to reason about and test 🧠 Rule of thumb: Streams are for transforming data, not changing state. If you’ve ever debugged this in production 😅, you’re not alone. 👇 Have you hit a tricky Java stream bug before? Share it. #Java #CleanCode #BackendDevelopment #SpringBoot #SoftwareEngineering

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