Spring MVC打印@RequestBody、@Response日志

问题描述：

使用JSON接收前端参数时， SpringMVC默认输出日志如下：

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

如果自己实现参数打印， 则需要从reqeust.getInputStream中获取JSON内容， 但是由于流只能读取一次， 所以会导致后续SpringMVC解析参数异常。
网上找到一种比较解决方法： 用HttpRequestWrapper重新封装Reqeust， 使打印日志后SpringMVC能正常解析HttpReqeust。这种方法比较麻烦, 这里不去研究

这里主要说说Spring提供的较好的解决方案：

可以通过自定义RequestBodyAdvisor、ResponseBodyAdvisor来实现日志输出。

RequestBodyAdvisor可以获取到解析后的Controller方法参数对象。
ResponseBodyAdvisor可以获取到Controller方法返回值对象。

然后将他们注册到requestMappingHandlerAdapter：

// 继承WebMvcConfigurationSupport， 重写该方法
@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日志输出实现参考:

RequestBodyAdvisor实现参考：

// CustomerRequestBodyAdvisor.java
/**
* 打印请求参数日志
*/
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) {
        // 只处理@RequestBody注解了的参数
        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();
        
        // 参数对象转JSON字符串
        String jsonBody;
        if (StringHttpMessageConverter.class.isAssignableFrom(converterType)) {
            jsonBody = body.toString();
        } else {
            jsonBody = JSON.toJSONString(body, SerializerFeature.UseSingleQuotes);
        }
        
        // 自定义日志输出
        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实现参考:

// CustomerResponseBodyAdvisor.java
/**
* 打印响应值日志
*/
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) {
        // 响应值转JSON串输出到日志系统
        if (logger.isInfoEnabled()) {
            logger.info("{}: {}", request.getURI(), JSON.toJSONString(body, SerializerFeature.UseSingleQuotes));
        }
        return body;
    }

}