初识拦截器HandlerInterceptor -spring boot

spring 封装 request response 实现拦截器接口（源码还是清晰易懂的）

package org.springframework.web.servlet;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public interface HandlerInterceptor {
    boolean preHandle(HttpServletRequest var1, HttpServletResponse var2, Object var3) throws Exception;

    void postHandle(HttpServletRequest var1, HttpServletResponse var2, Object var3, ModelAndView var4) throws Exception;

    void afterCompletion(HttpServletRequest var1, HttpServletResponse var2, Object var3, Exception var4) throws Exception;
}

preHandle : 事件完成前
postHandle: 事件处理时
afterCompletion: 事件完成后

个人的理解就是将一件事情分成不同的时机点，在相应的时机点根据业务需要实现对应逻辑