springMVC interceptor

HandlerInterceptor

public class HandlerInterceptorDemo implements HandlerInterceptor {    @Override    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {        return false;    }    @Override    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {    }    @Override    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {    }}

WebRequestInterceptor

public class WebRequestInterceptorDemo implements WebRequestInterceptor {    @Override    public void preHandle(WebRequest webRequest) throws Exception {    }    @Override    public void postHandle(WebRequest webRequest, ModelMap modelMap) throws Exception {    }    @Override    public void afterCompletion(WebRequest webRequest, Exception e) throws Exception {    }}

说明：interceptor是在请求在适配之后，对具体的handler方法前后的业务处理。
interceptor并不会拦截到所有request，它只有在handlerMapping找到对应的映射之后才会起作用。