今天写了个拦截器对一些mapping做了些处理，写完之后突然很想看看拦截器是怎么加进spring里面。对着源码debug了一遍。又有了新的收获。
1.拦截器的实现
1.实现HandlerInterceptor
public class MyHandlerInterceptor implements HandlerInterceptor { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { System.out.println("---------preHandle--------"); return true; } /** * controller执行之后，且页面渲染之前调用 * @param request * @param response * @param handler * @param modelAndView * @throws Exception */ @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { System.out.println("---------postHandle--------"); } /** * 页面渲染之后调用，一般用于资源清理操作 * @param request * @param response * @param handler * @param ex * @throws Exception */ @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { System.out.println("---------afterCompletion--------"); }
2.将拦截器加入到拦截链里面去，这里可以实现
WebMvcConfigurer
也可以继承
WebMvcConfigurerAdapter
只是 WebMvcConfigurerAdapter这个类在Springboot2.0已经 Deprecated了，这部分内容我们后面再讲
@Component public class MyWebMvcConfigurerAdapter implements WebMvcConfigurer { @Override public void addInterceptors(InterceptorRegistry registry) { registry.addInterceptor(new MyHandlerInterceptor()); } }
接下来我们看看拦截是怎么被调用的,在 preHandle方法打断点
