SpringContextHolder工具类---通过springContextHolder静态注入实体Bean

秒速五厘米 2022-05-11 02:18 631阅读 0赞

/**
     * Copyright ©  All rights reserved.
     */
    import org.apache.commons.lang3.Validate;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.DisposableBean;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.ApplicationContextAware;
    import org.springframework.context.annotation.Lazy;
    import org.springframework.stereotype.Service;
    
    /**
     * 以静态变量保存Spring ApplicationContext, 可在任何代码任何地方任何时候取出ApplicaitonContext.
     */
    @Service
    @Lazy(false)
    public class SpringContextHolder implements ApplicationContextAware, DisposableBean {
    
        private static ApplicationContext applicationContext = null;
    
        private static Logger logger = LoggerFactory.getLogger(SpringContextHolder.class);
    
        /**
         * 取得存储在静态变量中的ApplicationContext.
         */
        public static ApplicationContext getApplicationContext() {
            assertContextInjected();
            return applicationContext;
        }
    
        /**
         * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
         */
        @SuppressWarnings("unchecked")
        public static <T> T getBean(String name) {
            assertContextInjected();
            return (T) applicationContext.getBean(name);
        }
    
        /**
         * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
         */
        public static <T> T getBean(Class<T> requiredType) {
            assertContextInjected();
            return applicationContext.getBean(requiredType);
        }
    
        /**
         * 清除SpringContextHolder中的ApplicationContext为Null.
         */
        public static void clearHolder() {
            if (logger.isDebugEnabled()) {
                logger.debug("清除SpringContextHolder中的ApplicationContext:" + applicationContext);
            }
            applicationContext = null;
        }
    
        /**
         * 实现ApplicationContextAware接口, 注入Context到静态变量中.
         */
        @Override
        public void setApplicationContext(ApplicationContext applicationContext) {
            SpringContextHolder.applicationContext = applicationContext;
        }
    
        /**
         * 实现DisposableBean接口, 在Context关闭时清理静态变量.
         */
        @Override
        public void destroy() throws Exception {
            SpringContextHolder.clearHolder();
        }
    
        /**
         * 检查ApplicationContext不为空.
         */
        private static void assertContextInjected() {
            Validate.validState(applicationContext != null, "applicaitonContext属性未注入, 请在applicationContext.xml中定义SpringContextHolder.");
        }
    }

通过此工具类解决在静态方法中需要使用到Bean实例，而Autowired注入的实例不支持在静态方法中使用的问题.~ 可以根据name或.class对象获取Bean实例