英文:
Question - @ComponentScan(basePackageClasses = AdminController.class) <- why has it broken my application?
问题
我遇到了一个问题，我无法理解，问题是：
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应用启动失败
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描述：
webService.controller.RequestController中的setApplicant方法的参数0需要一个类型为'com.service.applicant.Applicant'的bean，但找不到该bean。
操作：
请考虑在配置中定义一个类型为'com.service.applicant.Applicant'的bean。
我已经进行了一些研究，但我仍然无法解决这个问题，当我从主应用程序类中简单地删除了 @ComponentScan，问题就解决了。
我删除了：
//@ComponentScan(basePackageClasses = AdminController.class)
一切都好了，但我感到很好奇... 有人可以帮助我吗？
英文:
i was getting an issue which I couldn't understand, which was:
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APPLICATION FAILED TO START
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Description:
Parameter 0 of method setApplicant in webService.controller.RequestController required a bean of type 'com.service.applicant.Applicant' that could not be found.
Action:
Consider defining a bean of type 'com.service.applicant.Applicant' in your configuration.
I've done some researches but I still couldn't fixed this problem, when I simply removed the @ComponentScan from my Main Application Class and it worked.
I removed:
//@ComponentScan(basePackageClasses = AdminController.class)
Everything is fine, but i got curious... Can someone please help me?
答案1
得分: 0
你应该首先在类 Applicant 上使用 @Component 进行注解。
在你的主类上，使用 @Configuration、@EnableAutoConfiguration 和 @ComponentScan({ "com.service.applicant", "your.admin.controller.path" }) 对对象进行注解。
在类 RequestController 中，将类型为 Applicant 的属性使用 @Autowired 进行注解。
英文:
you should annotate the class Applicant with @Component first.
in your main class annotate the object with @Configuration, EnableAutoConfiguration and @ComponentScan({"com.service.applicant","your.admin.controller.path"}).
in the class RequestController annotate the property of type Applicant with @Autowire.
答案2
得分: 0
当您不显式使用@ComponentScan时，您的主类上的@SpringBootApplication注解中包含了@ComponentScan的实现（以及@EnableAutoConfiguration）。因此，所有标记为@Component（或类似的注解，如@Controller、@Service等）的类都会被自动扫描，前提是它们与主类在同一个包或子包中定义。
现在在您的情况下，您在主类中添加了//@ComponentScan(basePackageClasses = AdminController.class)。这样做的效果是只为类AdminController创建了一个Bean，并忽略了所有其他类。
英文:
When you don't use @ComponentScan explicity, @SpringBootApplication annotation on your main class has implementation of @ComponentScan in it(along with @EnableAutoConfiguration). So all the classes marked as @component(or similar annotation like controller, service etc.) get scanned automatically provided they are in the same or sub-package where main class is defined.
Now in your case you added //@ComponentScan(basePackageClasses = AdminController.class) in your main class. What this did that it only created bean for the class AdminController and ignored all other classes.
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