攔截器HandlerInterceptorAdapter的postHandle和afterCompletion無法獲取response返回值問題

緣起
有一個需求，在進入controller之前驗證調用次數是否超過限制，在響應之后判斷是否正常返回，對調用次數進行+1，發現帶@RestController的類和帶@ResponseBody的方法在被調用后response會直接寫入輸出流，在postHandle和afterCompletion這兩個方法執行之前就已經把數據返回，導致這兩個方法里面的response根本獲取不到響應數據(也無法拿到頭信息等)。

解決方案
先解釋一下為什么不用過濾器，因為這個需求是攔截帶某個特定注解的controller方法，還需要獲取到這個注解里面的一些數據，因此Filter方案沒法滿足這樣的需求。怎么解決這個問題呢？那就是使用@ControllerAdvice，這個注解標注的類需要實現ResponseBodyAdvice，這樣在response返回前會調用這個類的beforeBodyWrite方法，我們就在beforeBodyWrite方法里面做文章，來進行“曲線救國”。代碼：

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

import java.lang.reflect.Method;

/**
 **/
@ControllerAdvice
public class ApiResponseBody implements ResponseBodyAdvice<RestResult> {

    private static final Logger logger = LoggerFactory.getLogger(ApiResponseBody.class);
    @Autowired
    private RedisClientWrapper redisClientWrapper;

    @Override
    public boolean supports(MethodParameter methodParameter, Class<? extends HttpMessageConverter<?>> aClass) {

        Method method = methodParameter.getMethod();
        return method.isAnnotationPresent(InvokeLimit.class);
    }

    @Override
    public RestResult beforeBodyWrite(RestResult restResult, MethodParameter methodParameter, MediaType mediaType, Class<? extends HttpMessageConverter<?>> aClass, ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse) {
        logger.info("調用限制攔截器進入次數增加");
        if(ResultEnums.SUCCESS.getCode().equals(restResult.getCode())){
            String appId =  methodParameter.getMethod().getAnnotation(InvokeLimit.class).value();
            String cusNo = serverHttpRequest.getHeaders().get(BussConstant.INVOKE_HEADER_CUS_NO).get(0);
            String times = redisClientWrapper.increment(appId + ":" + BussConstant.INVOKE_NUM_CURRENT_PREFIX + cusNo);
            logger.info("調用限制攔截器次數增加完成，cusNo={}，appId={}，當前次數為：{}",cusNo,appId,times);
        }

        return restResult;
    }
}

supports方法是來給定條件判斷是否該調用beforeBodyWrite，MethodParameter里面有各種數據，其中就有我想要的：調用了哪個方法，從而獲得標注在上面的注解。beforeBodyWrite中就是我的邏輯，其中也包含MethodParameter，並且還有封裝了的request和response，非常靈活。
關鍵代碼：@seeorg.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor#writeWithMessageConverterswriteWithMessageConverters(@Nullable T value, MethodParameter returnType,ServletServerHttpRequest inputMessage, ServletServerHttpResponse outputMessage)

if (selectedMediaType != null) {
	selectedMediaType = selectedMediaType.removeQualityValue();
	for (HttpMessageConverter<?> converter : this.messageConverters) {
		GenericHttpMessageConverter genericConverter = (converter instanceof GenericHttpMessageConverter ?
				(GenericHttpMessageConverter<?>) converter : null);
		if (genericConverter != null ?
				((GenericHttpMessageConverter) converter).canWrite(targetType, valueType, selectedMediaType) :
				converter.canWrite(valueType, selectedMediaType)) {
                        //關鍵代碼      
			body = getAdvice().beforeBodyWrite(body, returnType, selectedMediaType,
					(Class<? extends HttpMessageConverter<?>>) converter.getClass(),
					inputMessage, outputMessage);
			if (body != null) {
				Object theBody = body;
				LogFormatUtils.traceDebug(logger, traceOn ->
						"Writing [" + LogFormatUtils.formatValue(theBody, !traceOn) + "]");
				addContentDispositionHeader(inputMessage, outputMessage);
				if (genericConverter != null) {
					genericConverter.write(body, targetType, selectedMediaType, outputMessage);
				}
				else {
					((HttpMessageConverter) converter).write(body, selectedMediaType, outputMessage);
				}
			}
			else {
				if (logger.isDebugEnabled()) {
					logger.debug("Nothing to write: null body");
				}
			}
			return;
		}
	}
}                   

注：同理還有RequestBodyAdvice-> @RequestBody等