/**
* @author luozhou
* @Description: 参数处理前置类,目前用于处理文章缓存刷新
* @date 2018/11/14 16:35
*/
public class RequestHandlerMethodArgumentResolver implements HandlerMethodArgumentResolver {
@Override
public boolean supportsParameter(MethodParameter parameter) {
return parameter.hasParameterAnnotation(Article.class);
}
@Override
public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
Article article=parameter.getParameterAnnotation(Article.class);
String id= webRequest.getParameter("id");
if (!EmptyUtils.isEmpty(article)){
String method=article.method();
switch (method){
case CacheMethodConstant.UPDATE:
EssayRefresh.getNeedRefreshMap().put(id,CacheMethodConstant.UPDATE);
break;
case CacheMethodConstant.ADD:
EssayRefresh.getNeedRefreshMap().put(id,CacheMethodConstant.ADD);
break;
case CacheMethodConstant.DELETE:
EssayRefresh.getNeedRefreshMap().put(id,CacheMethodConstant.DELETE);
break;
}
}
return id;
}
}
执行时机在拦截器HandlerInterceptor实现类的preHandle之后,postHandle和afterCompletion之前;
preHandle:在业务处理器处理请求之前被调用。预处理,可以进行编码、安全控制、权限校验等处理;
postHandle:在业务处理器处理请求执行完成后,生成视图之前执行。后处理(调用了Service并返回ModelAndView,但未进行页面渲染),有机会修改ModelAndView (这个博主就基本不怎么用了);
afterCompletion:在DispatcherServlet完全处理完请求后被调用,可用于清理资源等。返回处理(已经渲染了页面);
HandlerMethodArgumentResolver 源码介绍参考:https://www.jianshu.com/p/f4653fe8c935