Spring MVC Interceptor 实现性能监控的功能代码

import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse; import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.core.NamedThreadLocal;import org.springframework.web.servlet.HandlerInterceptor;import org.springframework.web.servlet.ModelAndView;  public class PerformanceInterceptor implements HandlerInterceptor {   private final static Logger LOGGER = LoggerFactory.getLogger(PerformanceInterceptor.class);   private NamedThreadLocal<Long> startTimeThreadLocal = new NamedThreadLocal<Long>("performance");   @Override  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)      throws Exception {    startTimeThreadLocal.set(System.currentTimeMillis());    return true;  }   @Override  public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,      ModelAndView modelAndView) throws Exception {    return;  }   @Override  public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)      throws Exception {    long currentTime = System.currentTimeMillis();    long executeTime = currentTime - startTimeThreadLocal.get();    LOGGER.info("uri：{} 执行了 {} 毫秒", request.getRequestURI(), executeTime);  } }