初識攔截器HandlerInterceptor -spring boot

spring 封裝 request response 實現攔截器接口（源碼還是清晰易懂的）

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: 事件處理時
afterCompletion: 事件完成后

個人的理解就是將一件事情分成不同的時機點，在相應的時機點根據業務需要實現對應邏輯