Is Keyset Thread Safe?

3 Answers. keySet() is thread safe.

Is ConcurrentHashMap keySet thread-safe?

ConcurrentHashMap class is thread-safe i.e. multiple threads can operate on a single object without any complications. At a time any number of threads are applicable for a read operation without locking the ConcurrentHashMap object which is not there in HashMap.

Is using thread-safe?

A MessageService object is effectively immutable since its state can't change after its construction. Hence, it's thread-safe. Moreover, if MessageService were actually mutable, but multiple threads only have read-only access to it, it's thread-safe as well.