package com.holpe.tool; import org.springframework.beans.BeansException; import org.springframework.beans.factory.NoSuchBeanDefinitionException; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; public class SpringContextUtil implements ApplicationContextAware { private static ApplicationContext applicationContext; // Spring应用上下文环境 /** * 实现ApplicationContextAware接口的回调方法,设置上下文环境 * * @param applicationContext * @throws BeansException */ @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { SpringContextUtil.applicationContext = applicationContext; } /** * @return ApplicationContext */ public static ApplicationContext getApplicationContext() { return applicationContext; } /** * 获取对象 * * @param name * @return Object 一个以所给名字注册的bean的实例 * @throws BeansException */ public static Object getBean(String name) throws BeansException { return applicationContext.getBean(name); } /** * 获取类型为requiredType的对象 * 如果bean不能被类型转换,相应的异常将会被抛出(BeanNotOfRequiredTypeException) * * @param name * bean注册名 * @param requiredType * 返回对象类型 * @return Object 返回requiredType类型对象 * @throws BeansException */ public static Object getBean(String name, Class requiredType) throws BeansException { return applicationContext.getBean(name, requiredType); } /** * 如果BeanFactory包含一个与所给名称匹配的bean定义,则返回true * * @param name * @return boolean */ public static boolean containsBean(String name) { return applicationContext.containsBean(name); } /** * 判断以给定名字注册的bean定义是一个singleton还是一个prototype。 * 如果与给定名字相应的bean定义没有被找到,将会抛出一个异常(NoSuchBeanDefinitionException) * * @param name * @return boolean * @throws NoSuchBeanDefinitionException */ public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException { return applicationContext.isSingleton(name); } /** * @param name * @return Class 注册对象的类型 * @throws NoSuchBeanDefinitionException */ public static Class getType(String name) throws NoSuchBeanDefinitionException { return applicationContext.getType(name); } /** * 如果给定的bean名字在bean定义中有别名,则返回这些别名 * * @param name * @return * @throws NoSuchBeanDefinitionException */ public static String[] getAliases(String name) throws NoSuchBeanDefinitionException { return applicationContext.getAliases(name); } }
注意:如果不在applicationContext.xml中配置该实现类的话,applicationContext一直没有被初始化
applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"> <import resource="bean.xml"/> [color=red] <bean class="com.holpe.tool.SpringContextUtil" />[/color] </beans>