场景
在Spring应用开发中，为简化代码或者在静态方法中获取Spring应用的上下文，需要把SpringContext设置到类属性上。经过对源码的分析和实践，使用Spring的事件监听器监听ApplicationPreparedEvent事件是最佳的方式。
通过ApplicationPreparedEvent类的注释可知，该事件是在ApplicationContext创建完成后（未刷新前）发布的，也就是说我们收到该事件通知的时间比任何业务Bean初始化的时间都早。
实现
创建SpringContextUtil
@UtilityClass
public class SpringContextUtil {private static Boolean isDev;private static ApplicationContext applicationContext;public static ApplicationContext getApplicationContext() {if (applicationContext == null) {throw new RuntimeException("应用上下文未初始化完成");}return applicationContext;}/*** 是否是开发模式** @return 是否开发模式*/public static boolean isDev() {if (isDev == null) {Environment environment = getApplicationContext().getEnvironment();String[] activeProfiles = environment.getActiveProfiles();for (String activeProfile : activeProfiles) {if (JudgerConst.PROFILE_DEV.equalsIgnoreCase(activeProfile.trim())) {isDev = Boolean.TRUE;break;}}if (isDev == null) {isDev = Boolean.FALSE;}}return isDev;}public static <T> T getBean(Class<T> clazz) {return getApplicationContext().getBean(clazz);}public static <T> T getBean(String name, Class<T> clazz) {return getApplicationContext().getBean(name, clazz);}public static <T> T getTryBean(Class<T> clazz) {try {return getBean(clazz);} catch (Exception ignored) {}return null;}public static void initApplicationContext(ApplicationContext applicationContext) {if (applicationContext != null) {SpringUtil.applicationContext = applicationContext;}}
}
创建AppContextInitListener
@Slf4j
public class AppContextInitListener implements ApplicationListener<ApplicationPreparedEvent> {@Overridepublic void onApplicationEvent(ApplicationPreparedEvent event) {log.info("Load app context");SpringUtil.initApplicationContext(event.getApplicationContext());}
}
注册监听器
# META-INF/spring.factories
org.springframework.context.ApplicationListener=\cn.cpoet.judger.support.AppContextInitListener
原文地址：https://www.cpoet.cn/post/framework/spring/spring-context-util/
