Java培训之多个拦截方法的执行顺序

  • 关于执行顺序

com.atguigu.springmvc.interceptors.FirstHandlerInterceptor – preHandle

com.atguigu.springmvc.interceptors.SecondHandlerInterceptor – preHandle

************************************biz method*******************************

com.atguigu.springmvc.interceptors.SecondHandlerInterceptor – postHandle

com.atguigu.springmvc.interceptors.FirstHandlerInterceptor – postHandle

com.atguigu.springmvc.interceptors.SecondHandlerInterceptor – afterCompletion

com.atguigu.springmvc.interceptors.FirstHandlerInterceptor – afterCompletion

  • 执行顺序图解

java培训

  • 从源代码的执行角度分析流程:

boolean applyPreHandle(HttpServletRequest request, HttpServletResponse response) throws Exception {

if (getInterceptors() != null) {

for (int i = 0; i < getInterceptors().length; i++) {

HandlerInterceptor interceptor = getInterceptors()[i];

if (!interceptor.preHandle(request, response, this.handler)) {

triggerAfterCompletion(request, response, null);

return false;

}

this.interceptorIndex = i;

}

}

return true;

}

java培训

void applyPostHandle(HttpServletRequest request, HttpServletResponse response, ModelAndView mv) throws Exception {

if (getInterceptors() == null) {

return;

}

for (int i = getInterceptors().length – 1; i >= 0; i–) {

HandlerInterceptor interceptor = getInterceptors()[i];

interceptor.postHandle(request, response, this.handler, mv);

}

}

java培训

void triggerAfterCompletion(HttpServletRequest request, HttpServletResponse response, Exception ex)

throws Exception {

 

if (getInterceptors() == null) {

return;

}

for (int i = this.interceptorIndex; i >= 0; i–) {

HandlerInterceptor interceptor = getInterceptors()[i];

try {

interceptor.afterCompletion(request, response, this.handler, ex);

}

catch (Throwable ex2) {

logger.error(“HandlerInterceptor.afterCompletion threw exception”, ex2);

}

}

}

java培训

java培训

  • 源码分析:分析interceptorIndex的值情况

java培训


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