如何在 spring 过滤器中获取请求正文参数？

Question

I want to log the request params in the http request via Spring filter or aspect. I tried different ways but either request params are null or method is not called. I am using POSTMAN and it's a POST request

http://localhost:8080/AvailableData

sample request body:

{"keyUserAgent":"CFNetwork/1209 Darwin/20.2.0","locale":"en_US","eid":"8904977033","sessionId":"VGA-G20201030-776878787-1AD5-11EB-895C-H78789GJJH"}

method 1: here "@Override" method of beforeRequest() is called but overloaded method that I created is not called(I added @RequestBody to get the body as per other solutions).

@Component
public class CustomLoggingFilter extends AbstractRequestLoggingFilter {
      
            protected void beforeRequest(HttpServletRequest request, String message,@RequestBody RequestDTO requestBody) {
            requestBody.getKeyUserAgent();
            requestBody.getEid();
            System.out.println("Eid: "+requestBody.getEid());
            System.out.println("getKeyUserAgent: "+requestBody.getKeyUserAgent());
            
        }  
        
    }

method 2: here it is coming as null

@Aspect
@Component
@Order(1)
public class LogAspect {

    private final static Logger logger = LoggerFactory.getLogger(LoggerAspect.class);
      @Around("allControllerMethods() && args(..,@annotation(org.springframework...RequestBody) requestBody) ")
      public Object controllerEvents(ProceedingJoinPoint jp, Object requestBody) throws Throwable {
            
          ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
             HttpServletRequest request = attributes.getRequest();
             MethodSignature signature = (MethodSignature) jp.getSignature();
              Method method = signature.getMethod();
              Object resObject = jp.proceed();
              Object sessionId = attributes.getSessionId()
              if (requestBody != null) {
                  String keyUserAgent = request.getParameter("keyUserAgent");
                  System.out.println("keyUserAgent : " + keyUserAgent);
                  
                }
              
          return resObject;
      } 

Answer 1

First of all, there is a problem with reading data from HttpRequest for logging and later for processing as class HttpServletRequest only allows to read its contents once, and any repeating attempt to read it will cause an Exception. So, spring boot provides a solution for that with usage of class ContentCachingRequestWrapper . The idea is that you read the entire context of your request once in the filter and copy the contents into your wrapper class that allows multiple reads. After that, you continue the chain with your wrapper class (that indirectly implements HttpServletRequest). So now in one of your filters (that must be configured after the filter that replaces HttpServletRequest with ContentCachingRequestWrapper you can read and log your request parameters and later on you still can read your request for handling it. I implemented this in our project and it works like a charm. Here are few links to the articles explaining how to do it. Reading HttpServletRequest Multiple Times in Spring , Java Code Examples for org.springframework.web.util.ContentCachingRequestWrapper