java - spring mvc拦截器如何获取方法执行流程

Question

我想获得 spring mvc 项目中完整的执行流程及其执行时间。

public class MetricsInterceptor extends HandlerInterceptorAdapter {

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    if (handler instanceof HandlerMethod) {
        HandlerMethod hm = (HandlerMethod) handler;
        Method method = hm.getMethod();
        if (method.getDeclaringClass().isAnnotationPresent(Controller.class)) {
            if (method.isAnnotationPresent(Metrics.class)) {
               // System.out.println(method.getAnnotation(Metrics.class).value());
                System.out.println(method.getName());
            }
        }
    }
    return super.preHandle(request, response, handler);
}

@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    super.postHandle(request, response, handler, modelAndView);
}

@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    super.afterCompletion(request, response, handler, ex);
}

}

我正在获取带有 @Metrics 注释的 Controller 类和方法来记录一些方法的指标。我想要的是获取整个方法执行流程( Controller -->服务-->DAO)以及每个方法所花费的时间。无论如何可以在 postHandle() 或 afterCompletion() 中获取该信息。请提出建议。

Answer 1

使用 Spring AOP Around 建议可以实现这一点。

编写一个将拦截的切入点

• 包及其子包中公共(public)方法的所有执行
• 并且属于包及其子包
• Controller 层
• 服务层(可选择仅限于特定服务)
• DAO 层

然后写下周围建议如下

@Component
@Aspect
public class TraceAdvice {

    @Around("execution(* com.test..*(..))  &&" + " (within(com.test.controller..*) || "
        + "(within(com.test.service..*) && this(com.test.service.TestService)) || " + "within(com.test.dao..*))")
    public Object traceCall(ProceedingJoinPoint pjp) throws Throwable {
        /* This will hold our execution details in reverse order 
         * i.e. last method invoked would appear first.
         * Key = Full qualified name of method
         * Value = Execution time in ms
         */
        Map<String, Long> trace = null;
        Signature sig = pjp.getSignature();
        // Get hold of current request
        HttpServletRequest req = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
        // check if we are in controller (I used RestController modify it if Controller is required instead) 
        boolean isController = sig.getDeclaringType().isAnnotationPresent(RestController.class);
        if (isController) {
            // set the request attributte if we are in controller
            trace = new LinkedHashMap<>();
            req.setAttribute("trace", trace);
        } else {
            // if its not controller then read from request atributte
            trace = (Map<String, Long>) req.getAttribute("trace");
        }
        Object result = null;
        StopWatch watch = new StopWatch();
        try {
            // start the timer and invoke the advised method
            watch.start();
            result = pjp.proceed();
        } finally {
            // stop the timer 
            watch.stop();
            String methodName = sig.getDeclaringTypeName() + "." + sig.getName();
            // make entry for the method name with time taken
            trace.put(methodName, watch.getTotalTimeMillis());
            if (isController) {
                // since controller method is exit point print the execution trace
                trace.entrySet().forEach(entry -> {
                    System.out.println("Method " + entry.getKey() + " took " + String.valueOf(entry.getValue()));
                });
            }
        }
        return result;
    }
}

进行必要的配置后，示例输出应如下所示

Method com.test.dao.TestDAO.getTest took 350
Method com.test.service.TestService.getTest took 1954
Method com.test.controller.TestController.getTest took 3751

或者可以为每个拦截特定包编写三个切入点和相应的 Around 建议，以便消除检查 Controller 的 if-else 部分

我已经测试了设置

• Spring 4.3.2 发布
• AspectJ 1.7.4
• JDK 1.8
• Tomcat 8.0

如果有任何问题，请在评论中告知。