获取Spring应用环境上下文bean

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

/**
 * Copy from https://code.google.com/p/carljavautils/source/browse/trunk/+carljavautils/src/com/hmw/spring/SpringContextUtil.java?r=25
 * */
@Component
@Scope(value=BeanDefinition.SCOPE_SINGLETON)
public class SpringContext implements ApplicationContextAware {
    /** Spring应用环境上下文 */
    private static ApplicationContext applicationContext;

    /**
     * 实现ApplicationContextAware接口的回调方法，设置上下文环境
     *
     * @param applicationContext
     * @throws BeansException
     */
    public void setApplicationContext(ApplicationContext applicationContext)
            throws BeansException {
        SpringContext.applicationContext = applicationContext;
    }

    /**
     * @return ApplicationContext
     */
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    /**
     * 获取对象
     *
     * @param name
     * @return 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
     *
     * @param name
     *            bean注册名
     * @param requiredType
     *            返回对象类型
     * @return 返回requiredType类型对象
     * @throws BeansException
     *             如果bean不能被类型转换
     */
    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。
     *
     * @param name
     * @return boolean
     * @throws NoSuchBeanDefinitionException
     *             如果与给定名字相应的bean定义没有被找到
     */
    public static boolean isSingleton(String name)
            throws NoSuchBeanDefinitionException {
        return applicationContext.isSingleton(name);
    }

    /**
     * @param name
     * @return 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);
    }
}