java - 如何在 Spring boot 应用程序中为拦截器编写自定义启用注释？

Question

是否可以编写自定义启用注释来为 Spring Boot 应用程序启用拦截器。

这是我的代码，

配置

@Configuration
public class CustomConfig extends WebMvcConfigurerAdapter {

    @Autowired
    CustomInterceptor interceptor;

    @Override
      public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(interceptor);
    }

}

拦截器

@Component
public class CustomInterceptor implements HandlerInterceptor {

    @Override
    public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
            throws Exception {

        System.err.println("Executed!!!afterCompletion");

    }

    @Override
    public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
            throws Exception {
        System.err.println("Executed!!!postHandle");

    }

    @Override
    public boolean preHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2) throws Exception {
        // TODO Auto-generated method stub
        return true;
    }

}

自定义注释

@Documented
@Retention(RUNTIME)
@Target(TYPE)
@Import(CustomConfig.class)
public @interface EnableCustomConfig {

}

我想仅当此注释时启用此拦截器

@EnableCustomConfig

出现在主类中，

@SpringBootApplication
@EnableAutoConfiguration
@EnableCustomConfig
public class CustomEnableApplication {

    public static void main(String[] args) {
        SpringApplication.run(CustomEnableApplication.class, args);
    }
}

这可以在 Spring Boot 中实现吗？如果是的话，请告诉我如何做。

Answer 1

这里有几个选项。首先，我想我会完全跳过注释。您可以简单地扩展接口(interface):

public CustomInterceptor extends HandlerInterceptor {}

让您想要的拦截器实现此接口(interface)，并使用 ApplicationContext 来确定哪些 Spring bean 实现此接口(interface):

@Autowired
private ApplicationContext applicationContext;

@Override
public void addInterceptors(InterceptorRegistry registry) {
    Map<String, CustomInterceptor> interceptors = applicationContext.getBeansOfType(CustomInterceptor.class);
    for(CustomInterceptor interceptor : interceptors.values()){
          registry.addInterceptor(interceptor);
    }
}

如果您决定使用注释，则可以使用与上述逻辑基本相同的逻辑。您将获得实现 HandlerInterceptor 接口(interface)的所有 bean，然后检查它们的注释。您可以通过以下方式检查 bean 的注释:

public boolean isAnnotatedWithMyAnnotation(Class clazz){
    return clazz.getAnnotation(EnableCustomConfig.class) == null ? false : true;
}