在 spring 引导中自动装配的 class 上自动装配和使用新关键字之间的区别？

Question

@Autowired
private EmployeeService employeeService;

vs

@Autowired
private EmployeeService employeeService = new EmployeeService();

Is using new EmployeeService() on autowired class different than just using new EmployeeService() ?

Answer 1

If a bean for @Autowired is injected it will override your created object. But if there is no bean created you have a fallback (in this case new EmployeeService() . That might be helpful for tests but it's kind of an anti-pattern because normally you just want one of both behaviours.