The article explains why comparing two Integer objects with `==` returns true for values within -128 to 127 but false for larger numbers, detailing Java’s integer cache, reference vs. value equality, and the correct use of `.equals()` to avoid subtle bugs.
This article explores why using an Integer as a lock can cause synchronized to malfunction, demonstrates the issue with a ticket‑selling example, analyzes thread dumps and JVM bytecode, and presents reliable alternatives such as class‑level locks or map‑based lock objects.
This article explains why Java’s Integer autoboxing caches values between -128 and 127, causing the == operator to report true for those numbers, and shows how to avoid the pitfall by using equals() instead.
This article explains why the == operator returns true for small Integer values in Java, detailing the internal IntegerCache mechanism, demonstrating the behavior with code examples, and showing how reflection can manipulate the cache, highlighting both the benefits and potential pitfalls of this optimization.
