Singelton Bean Serving Concurrent Requests In Spring Boot

We have wonder many a time , how a single spring bean can serve so many concurrent request without corrupting data of Individual Requests .

Lets See this Service Class :-

@Service
class MyService {
  
  @Autowired
  MyFacade myFacade;

  public void doRun(){
    myFacade.doSomething()
  }
}

Here MyService Class bean is using the dependency of MyFacade and calling a method of that Class , But we can see that MyService class has no state of itself , whenever the bean of MyService Class will be created , No State will be there in it .

lets See another case :-

@Service
class MyService {
  
  int x = 10;
  
  @Autowired
  MyFacade myFacade;

  public void doRun(){
    myFacade.doSomething();
    x++;
  }
}

Here we can see our bean has some property which will be shared across threads which will be using its doRun method.

In Conclusion , To make our Spring Application serve concurrent requests in a multithreaded environment , we should always make Stateless Beans.