读取 RequestMapping 注解值

Question

为了能够对每个端点进行统计，我希望能够获得 @RequestMapping 注释值，即参数化版本。否则我的监控工具会将不同的 id 视为不同的 url：

@RequestMapping(value = "/customers/{customerId}/items/{itemId}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
  public ResponseEntity<ItemDetailsDto> getItemById(
      @PathVariable(value = "customerId") int customerId
      @PathVariable(value = "itemId") int itemId)
      throws Exception
  {
    //do stuff

    //I want this to be "/customers/{customerId}/items/{itemId}"
    //,not "/customers/15988/items/85"
    String s = ????
  }

如何在运行时获取/customers/{customerId}/items/{itemId}？ 我的工具允许我拦截方法并捕获其参数，因此我还可以监视 Spring 框架中的特定方法以捕获设置或获取某些东西。

Answer 1

你可以使用Java反射来做，你只需要这样做：

String s= this.getClass().getDeclaredMethod("getItemById", int.class, int.class).getAnnotation(RequestMapping.class).value();

getDeclaredMethod的第一个参数是方法的名称，其他参数是该方法的参数类型。

Answer 2

另一种方法是

private static final String URI_GET_ITEM_BY_ID ="/customers/{customerId}/items/{itemId}";

@RequestMapping(value = URI_GET_ITEM_BY_ID, method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
  public ResponseEntity<ItemDetailsDto> getItemById(
      @PathVariable(value = "customerId") int customerId
      @PathVariable(value = "itemId") int itemId)
      throws Exception
  {
    //do stuff

    // Use URI_GET_ITEM_BY_ID

  }

更新 1：

假设控制器用@RestController注解

@RestController
public class SampleController {

      @RequestMapping(value = "/customers/{customerId}/items/{itemId}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
  public ResponseEntity<ItemDetailsDto> getItemById(
      @PathVariable(value = "customerId") int customerId
      @PathVariable(value = "itemId") int itemId)
      throws Exception
  {
    //do stuff

    //I want this to be "/customers/{customerId}/items/{itemId}"
    //,not "/customers/15988/items/85"
    String s = ????
  }

}

以下Aspect 可用于在不更改控制器方法的情况下获取 URI 路径。

@Aspect
@Component
public class RestControllerAspect {

    @Pointcut("@within(org.springframework.web.bind.annotation.RestController) && within(rg.boot.web.controller.*)")
    public void isRestController() {

    }

    @Before("isRestController()")
    public void handlePost(JoinPoint point) {
        MethodSignature signature = (MethodSignature) point.getSignature();
        Method method = signature.getMethod();

        // controller method annotations of type @RequestMapping
        RequestMapping[] reqMappingAnnotations = method
                .getAnnotationsByType(org.springframework.web.bind.annotation.RequestMapping.class);
        for (RequestMapping annotation : reqMappingAnnotations) {
            System.out.println(annotation.toString());
            for(String val : annotation.value()) {
                System.out.println(val);
            }
        }

    }
}

这会打印出来

@org.springframework.web.bind.annotation.RequestMapping(path=[], headers=[], method=[GET], name=, produces=[application/json], params=[], value=[/customers/{customerId}/items/{itemId}], consumes=[])
/customers/{customerId}/items/{itemId}

对于 URI 的请求：/customers/1234/items/5678

更新 2：

另一种方式是导入

import static org.springframework.web.servlet.HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE;
import org.springframework.web.context.request.RequestContextHolder;

并使用以下代码获取路径

 RequestAttributes reqAttributes = RequestContextHolder.currentRequestAttributes(); 
 String s = reqAttributes.getAttribute(BEST_MATCHING_PATTERN_ATTRIBUTE, 0);

这是改编自我的answer另一个问题。