网站建设导航栏变化,做物流网站的多少钱,做直播网站赚钱,嘉兴网为了了解 Spring 为什么会启动那么久#xff0c;于是看了看怎么统计一下加载 Bean 的耗时。
极简版
几行代码搞定。
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;import java.util.HashMap;
imp…为了了解 Spring 为什么会启动那么久于是看了看怎么统计一下加载 Bean 的耗时。
极简版
几行代码搞定。
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;import java.util.HashMap;
import java.util.Map;public class SpringBeanAnalyse implements BeanPostProcessor {private static final MapString, Long mapBeanTime new HashMap();Overridepublic Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {mapBeanTime.put(beanName, System.currentTimeMillis());return bean;}Overridepublic Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {Long begin mapBeanTime.get(beanName);if (begin ! null) {long ell System.currentTimeMillis() - begin;System.out.println(beanName 耗时: ell);}return bean;}
}使用方法
Bean
SpringBeanAnalyse SpringBeanAnalyse() {return new SpringBeanAnalyse();
}效果如图 问题是没有排序看比较费劲。
高配版
于是高配版出场了。它更为成熟壮健并有排序功能。 原理
Bean 启动时间抓取主要是围绕 Spring Bean 生命周期。BeanPostProcessor 相关方法 postProcessBeforeInstantiation: 实例化前postProcessAfterInstantiation: 实例化后postProcessBeforeInitialization: 初始化前postProcessAfterInitialization: 初始化后 注意实现MergedBeanDefinitionPostProcessor, 主要是为了调整当前 BeanPostProcessor的执行顺序到最后, 具体参考BeanPostProcessor注册流程 org.springframework.context.support.AbstractApplicationContext#refresh org.springframework.context.support.AbstractApplicationContext#registerBeanPostProcessors org.springframework.context.support.PostProcessorRegistrationDelegate#registerBeanPostProcessors 详见
源码
首先是一个 Bean。
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;Builder
Data
AllArgsConstructor
NoArgsConstructor
class Statistics {private String beanName;private long beforeInstantiationTime;private long afterInstantiationTime;private long beforeInitializationTime;private long afterInitializationTime;public long calculateTotalCostTime() {return calculateInstantiationCostTime() calculateInitializationCostTime();}public long calculateInstantiationCostTime() {return afterInstantiationTime - beforeInstantiationTime;}public long calculateInitializationCostTime() {return afterInitializationTime - beforeInitializationTime;}public String toConsoleString() {return \t getBeanName() \t calculateTotalCostTime() \t\n;}
}StartupTimeMetric源码
import com.ajaxjs.util.logger.LogHelper;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessor;
import org.springframework.beans.factory.support.MergedBeanDefinitionPostProcessor;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.core.PriorityOrdered;import java.util.*;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.stream.Collectors;/*** 用于调优的处理器*/
public class StartupTimeMetric implements InstantiationAwareBeanPostProcessor, PriorityOrdered, ApplicationListenerContextRefreshedEvent, MergedBeanDefinitionPostProcessor {private static final LogHelper LOGGER LogHelper.getLog(StartupTimeMetric.class);private final MapString, Statistics statisticsMap new TreeMap();/*** InstantiationAwareBeanPostProcessor 中自定义的方法 在方法实例化之前执行 Bean 对象还没有*/Overridepublic Object postProcessBeforeInstantiation(Class beanClass, String beanName) throws BeansException {String beanClassName beanClass.getName();Statistics s Statistics.builder().beanName(beanClassName).build();s.setBeforeInstantiationTime(System.currentTimeMillis());statisticsMap.put(beanClassName, s);return null;}/*** InstantiationAwareBeanPostProcessor 中自定义的方法 在方法实例化之后执行 Bean 对象已经创建出来了*/Overridepublic boolean postProcessAfterInstantiation(Object bean, String beanName) throws BeansException {String beanClassName bean.getClass().getName();Statistics s statisticsMap.get(beanClassName);if (s ! null)s.setAfterInstantiationTime(System.currentTimeMillis());return true;}/*** BeanPostProcessor 接口中的方法 在 Bean 的自定义初始化方法之前执行 Bean 对象已经存在了*/Overridepublic Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {String beanClassName bean.getClass().getName();Statistics s statisticsMap.getOrDefault(beanClassName, Statistics.builder().beanName(beanClassName).build());s.setBeforeInitializationTime(System.currentTimeMillis());statisticsMap.putIfAbsent(beanClassName, s);return bean;}/*** BeanPostProcessor 接口中的方法 在 Bean 的自定义初始化方法执行完成之后执行 Bean 对象已经存在了*/Overridepublic Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {String beanClassName bean.getClass().getName();Statistics s statisticsMap.get(beanClassName);if (s ! null)s.setAfterInitializationTime(System.currentTimeMillis());return bean;}Overridepublic int getOrder() {return PriorityOrdered.HIGHEST_PRECEDENCE;}private static final AtomicBoolean START_LOCK new AtomicBoolean(false);Overridepublic void onApplicationEvent(ContextRefreshedEvent event) {LOGGER.info(Spring 容器启动完成);if (START_LOCK.compareAndSet(false, true)) {ListStatistics sList statisticsMap.values().stream().sorted(Comparator.comparing(Statistics::calculateTotalCostTime).reversed()).collect(Collectors.toList());StringBuilder sb new StringBuilder();sList.forEach(_s - sb.append(_s.toConsoleString()));LOGGER.info(ApplicationStartupTimeMetric:\n sb);}}Overridepublic void postProcessMergedBeanDefinition(RootBeanDefinition beanDefinition, Class? beanType, String beanName) {}
}参见《应用启动加速-并发初始化spring bean》
