[VV127] The Java 21 Newsletter: 💻 Java Interfaces: Can You Override That Method? Let's Set the Record Straight
[VV127] The Java 21 Newsletter: 💻 Java Interfaces: Can You Override That Method? Let's Set the Record Straight
Interfaces in Java can now do much more than just define abstract methods. Since Java 8+, we can also use default, static, and even private methods — and when interfaces extend each other, you may wonder:
Can this method override that one?
Can this method override that one?
Let’s answer that with a definitive override matrix ✅❌
🧪 Reference Interface
We’ll use this base interface to discuss method overrides:
Now, say we create a subinterface:
📊 Override Possibilities Matrix
🔁 Hiding means the static method is not overridden but redefined in the subinterface or implementing class.
💡 Examples
✅ Valid
❌ Invalid
🧠 Key Takeaways
- ✅ You can override abstract or default methods with abstract or default.
- ❌ You cannot override them with static.
- ✅ You can redeclare static or private methods as any type — but they do not override, just hide or coexist.
- 📌 Private methods are invisible to the subinterface, so any redefinition is treated as a new method.
🧾 Save This Matrix!
🔖 Tags
#Java #JavaInterfaces #Java8 #Java21 #JavaCertification #OverrideVsHide #SoftwareEngineering #CleanCode #JavaTips #TechInterview
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