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。
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;
}
}
