spring三种注入方式

构造器注入

@Autowired
    public AService(BService bService) {
        this.bService = bService;
    }

set注入 (重点)

AService aService;
    @Autowired
    public void setaService(AService aService) {
        this.aService = aService;
    }

属性注入

@Autowired
    AService aService;