Spring MVC打印@RequestBody、@Response日誌

問題描述：

使用JSON接收前端參數時， SpringMVC默認輸出日誌如下：

o.s.web.servlet.DispatcherServlet : POST "/example_project/app/login", parameters={}
parameters={}無法打印出JSON消息內容。

如果自己實現參數打印， 則需要從reqeust.getInputStream中獲取JSON內容， 但是由於流只能讀取一次， 所以會導致後續SpringMVC解析參數異常。
網上找到一種比較解決方法： 用HttpRequestWrapper重新封裝Reqeust， 使打印日誌後SpringMVC能正常解析HttpReqeust。這種方法比較麻煩, 這裏不去研究

這裏主要說說Spring提供的較好的解決方案：

可以通過自定義RequestBodyAdvisor、ResponseBodyAdvisor來實現日誌輸出。

RequestBodyAdvisor可以獲取到解析後的Controller方法參數對象。
ResponseBodyAdvisor可以獲取到Controller方法返回值對象。

然後將他們註冊到requestMappingHandlerAdapter：

// 繼承WebMvcConfigurationSupport， 重寫該方法
@Override
@Bean
public RequestMappingHandlerAdapter requestMappingHandlerAdapter() {
    RequestMappingHandlerAdapter adapter = super.requestMappingHandlerAdapter();
    adapter.setRequestBodyAdvice(Lists.newArrayList(new CustomerRequestBodyAdvisor()));
    adapter.setResponseBodyAdvice(Lists.newArrayList(new CustomerResponseBodyAdvisor()));
    return adapter;
}

---

另附CustomerRequestBodyAdvisor、CustomerResponseBodyAdvisor日誌輸出實現參考:

RequestBodyAdvisor實現參考：

// CustomerRequestBodyAdvisor.java
/**
* 打印請求參數日誌
*/
public class CustomerRequestBodyAdvisor extends RequestBodyAdviceAdapter {

    private static final Logger logger = LoggerFactory.getLogger(CustomerRequestBodyAdvisor.class);

    @Override
    public boolean supports(MethodParameter methodParameter, Type targetType, Class<? extends HttpMessageConverter<?>> converterType) {
        // 只處理@RequestBody註解了的參數
        return methodParameter.getParameterAnnotation(RequestBody.class) != null;
    }

    @Override
    public Object afterBodyRead(Object body, HttpInputMessage inputMessage, MethodParameter parameter, Type targetType, Class<? extends HttpMessageConverter<?>> converterType) {
        Method method = parameter.getMethod();
        
        // 參數對象轉JSON字符串
        String jsonBody;
        if (StringHttpMessageConverter.class.isAssignableFrom(converterType)) {
            jsonBody = body.toString();
        } else {
            jsonBody = JSON.toJSONString(body, SerializerFeature.UseSingleQuotes);
        }
        
        // 自定義日誌輸出
        if (logger.isInfoEnabled()) {
            logger.info("{}#{}: {}", parameter.getContainingClass().getSimpleName(), method.getName(), jsonBody);
            //            logger.info("json request<=========method:{}#{}", parameter.getContainingClass().getSimpleName(), method.getName());
        }
        return super.afterBodyRead(body, inputMessage, parameter, targetType, converterType);
    }
}

---

ResponseBodyAdvisor實現參考:

// CustomerResponseBodyAdvisor.java
/**
* 打印響應值日誌
*/
public class CustomerResponseBodyAdvisor implements ResponseBodyAdvice<Object> {
    private static final Logger logger = LoggerFactory.getLogger(CustomerResponseBodyAdvisor.class);

    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        return AbstractJackson2HttpMessageConverter.class.isAssignableFrom(converterType)
                || returnType.getMethod().isAnnotationPresent(ResponseBody.class);
    }

    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        // 響應值轉JSON串輸出到日誌系統
        if (logger.isInfoEnabled()) {
            logger.info("{}: {}", request.getURI(), JSON.toJSONString(body, SerializerFeature.UseSingleQuotes));
        }
        return body;
    }

}