利用Spring MVC 的 Interceptor 实现个简易的性能监控,计算一下每个url的执行时间。
在 preHandle 方法中记录当前的时间戳到线程局部变量里,然后在afterCompletion方法中,用当前的时间戳剪掉线程局部变量里的时间戳得出个运行时间,并记录到log里。
这只是个简易的性能监控,如果想长期正式的监控性能,请选择其它成熟的产品。
Interceptor
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); } }
这里的是NamedThreadLocal没啥神器的,源码如下:
package org.springframework.core; import org.springframework.util.Assert; public class NamedThreadLocal<T> extends ThreadLocal<T> { private final String name; public NamedThreadLocal(String name) { Assert.hasText(name, "Name must not be empty"); this.name = name; } @Override public String toString() { return this.name; } }
定义完Interceptor,注册即可。
import java.util.List; import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean; import org.springframework.boot.web.filter.OrderedCharacterEncodingFilter; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.http.converter.HttpMessageConverter; import org.springframework.web.filter.CharacterEncodingFilter; import org.springframework.web.servlet.config.annotation.InterceptorRegistry; import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry; import org.springframework.web.servlet.config.annotation.ViewControllerRegistry; import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter; import com.vnierlai.scm.webapp.interceptor.PerformanceInterceptor; @Configuration public class WebMvcConfigurer extends WebMvcConfigurerAdapter { @Bean @ConditionalOnMissingBean(CharacterEncodingFilter.class) public CharacterEncodingFilter characterEncodingFilter() { CharacterEncodingFilter filter = new OrderedCharacterEncodingFilter(); filter.setEncoding("UTF-8"); return filter; } @Override public void addInterceptors(InterceptorRegistry registry) { registry.addInterceptor(new PerformanceInterceptor()).addPathPatterns("/**"); super.addInterceptors(registry); } @Override public void addResourceHandlers(ResourceHandlerRegistry registry) { registry.addResourceHandler("/webjars/**").addResourceLocations("classpath:/META-INF/resources/webjars/"); // registry.addResourceHandler("/resources/**").addResourceLocations("/resources/"); } }