How to create common '/ping' API resource in abstract BaseController?

Question

我有 BaseController：

@Controller
public abstract class BaseController {

    /**
     * The Logger for this class hierarchy
     */
    protected Logger logger = LoggerFactory.getLogger(this.getClass());

    @RequestMapping(value = "/ping", produces = MediaType.APPLICATION_JSON_VALUE)
    public ServiceResponse<?> ping() {
        ServiceResponse<Object> serviceResponse = new ServiceResponse<>(ResponseStatus.SUCCESS);
        return serviceResponse;
    }
}

还有一些像这样扩展这个 BaseController 的其他控制器：

@RestController
@RequestMapping(value= "/admin")
public class AdminController extends BaseController {

    @RequestMapping(
            value = "/all", 
            method = RequestMethod.GET,
            produces = MediaType.APPLICATION_JSON_VALUE)
    public ServiceResponse<List<Account>> getAll() {
        ServiceResponse<List<Account>> serviceResponse = accountService.getAll();
        return serviceResponse;
    }
}

但是一旦我移动 ping() 资源 BaseController，我就会在服务器启动时出错：

2016-04-23 21:31:39.862 ERROR 2335 --- [           main] o.s.boot.SpringApplication               : Application startup failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource [org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'clientController' method 
public ca.gatin.api.response.ServiceResponse<?> ca.gatin.api.controller.BaseController.ping()
to {[/admin/ping],produces=[application/json]}: There is already 'adminController' bean method
public ca.gatin.api.response.ServiceResponse<?> ca.gatin.api.controller.BaseController.ping() mapped.
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1578) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839) ~[spring-context-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) ~[spring-context-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:766) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:361) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1191) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1180) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at ca.gatin.TodoAppApplication.main(TodoAppApplication.java:10) [classes/:na]

只是，我不想在多个控制器中复制 ping() 资源。我怎样才能把它正确地移动到 BaseController？

Answer 1

我看你好像在用另一个

class ClientController extends BaseController

ClientController 和 AdminController 都将 /ping 映射到它们继承的方法 ping()。 Spring 只能将 /ping 映射到一个或另一个，这就是你得到异常的原因。

你在写

我不想在多个控制器中复制 ping() 资源

而且没有必要这样做。将您的 ping() 方法放入其自己的控制器中，将其从 BaseControler 中删除，仅此而已。

无论如何，我不建议在控制器中使用继承，它使事情变得更加复杂，而不是帮助。