Is this design of Spring singleton beans thread safe?

Question

Consider the following Spring Service class. The spring scope defined is Singleton. The two service beans auto-wired as fields in the class below have similar structure - they t

Answer 1

Spring doesn't guarantee thread-safety, when it says beans are singleton. If you make bean of singleton scope in spring, it simply mean that a single object instance per Spring IoC container is created. But still that singleton-scoped bean class may not be thread safe in itself, so its programmer's responsibility to make the code thread safe.