如何获取自定义注释的@PathVariable 值？

Question

我有一个控制器：

@Authorised(id = "{personId}")
@RequestMapping(value = {"{personId}"}, method = GET)
public void test(@PathVariable PersonId personId) {
    System.out.println(personId); //gets personId
}

注释：

@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Authorised {
    String id() default "";
}

切入点：

@Pointcut("@annotation(Authorised)")
private void AuthorisedMethod() {}

必须获取 {personId} 值的方法不是字符串“{personId}”：

@Before("AuthorisedMethod()")
public void checkIfIsCurrentlyAuthenticated(JoinPoint joinPoint) throws NoSuchMethodException {
    MethodSignature signature = (MethodSignature) joinPoint.getSignature();
    String methodName = signature.getMethod().getName();
    Class<?>[] parameterTypes = signature.getMethod().getParameterTypes();
    Parameter[] parameters = signature.getMethod().getParameters();
    Authorised annotations = joinPoint.getTarget().getClass().getMethod(methodName, parameterTypes).getAnnotation(Authorised.class);
    String id = annotations.id();
    System.out.println(id); // prints: "{personId}"
    // do the chekcing
    throw new UnauthenticatedUserException();
}

能否实现以及如何实现？

更新：但是如果方法参数参数编号与切入点 args() 不匹配怎么办？我的意思是，如果特定方法有参数@PathVariable PersonId personId 等等，但 poincut 只需要知道 PersonId personId 怎么办？

就像@statut 说的你必须这样写 args()：args(personId,..)

Answer 1

例如，您可以修改@Before() 注释以具有PersonId 值并将此值传递给方面

@Before("AuthorisedMethod() && args(personId)")
public void checkIfIsCurrentlyAuthenticated(JoinPoint joinPoint, PersonId personId) throws NoSuchMethodException {}

为了测试它，我有以下方面：

@Aspect
@Component
public class SomeAspect {

    @Pointcut("@annotation(Authorised)")
    private void AuthorisedMethod() {
    }

    @Before("AuthorisedMethod() && args(personId)")
    public void checkIfIsCurrentlyAuthenticated(JoinPoint joinPoint, PersonId personId) throws NoSuchMethodException {
        System.out.println("aspect " + personId.getId());
    }

}

配置类：

@Configuration
@ComponentScan(basePackages = {"test"})
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class Config {
}

测试组件：

@Component
public class Test {

    @Authorised(id = "{personId}")
    public void test(PersonId personId) {
        System.out.println("component " + personId.getId()); //gets personId
    }
}

还有 testNG 的跑步者：

@ContextConfiguration(classes = Config.class)
public class TestRunner extends AbstractTestNGSpringContextTests {

    @Autowired
    test.Test test;

    @Test
    public void testName() {
        test.test(new PersonId("id"));
    }

}

当我运行它时，我会从方面打印"aspect id"，从调用的方法打印"component id"。

Answer 2

如果可能的话，您还可以使用 HandlerInterceptor 获取 RequestMapping URL 中 PathVariable 的值。

编写一个Handler类来拦截这个Request。

public class AuthorisedHandler extends HandlerInterceptorAdapter {

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
        throws Exception {
    if (!isResourceHandler(handler) && (handler instanceof HandlerMethod)) {

        HandlerMethod hm = (HandlerMethod) handler;
        Method method = hm.getMethod();

        Authorised authAnnotation = method.getAnnotation(Authorised.class);
        if (authAnnotation != null) {
            String personId = getPersonId(request);
            //Do all your validations Here
        }
    }
    return true;
}

@SuppressWarnings("rawtypes")
private String getPersonId(HttpServletRequest request) throws IOException {
    String personId = request.getParameter("personId");
    if(personId == null || personId.equals("")){
        Map pathVariables = (Map) request.getAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE);
        personId = (String) pathVariables.get("personId");
    }
    return personId;
}


private boolean isResourceHandler(Object handler) {
    return handler instanceof ResourceHttpRequestHandler;
}

}

而且你必须在 spring config xml 或 Spring Java Config 中配置这个 Handler bean。

<mvc:interceptors>
    <mvc:interceptor>
        <mvc:mapping path="/**"/>
        <bean class="com.**.AuthorisedHandler" />
    </mvc:interceptor>
</mvc:interceptors>

现在，所有的请求都将通过这个拦截器。只有带有@Authorised 注释的才会通过。