How does Optional behave in multithreaded code?

In Java, the Optional class is used to represent a value that may or may not be present. When it comes to multithreaded code, Optional behaves consistently as it is immutable, meaning its state cannot be changed after it is created. This immutability makes it a thread-safe option to handle possible null values across multiple threads.

However, the operations performed on Optional instances must be designed with concurrency in mind, especially when dealing with shared resources or states that may lead to unpredictable outcomes if not managed properly.

In multithreading scenarios, it's important to avoid using Optional to encapsulate mutable state, as this can lead to race conditions or visibility issues between threads. Instead, use Optional to handle values that are retrieved or computed in a thread-safe manner.