SpringContextHolder.java

/**
 * Copyright © 2012-2013 <a href="https://github.com/thinkgem/jeesite">JeeSite</a> All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 */
package com.hongqiang.shop.common.utils;

import java.util.Locale;

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.web.servlet.LocaleResolver;

/**
 * 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.
 * 
 * @author Zaric
 * @date 2013-5-29 下午1:25:40
 */
// @Service
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);
	}

	public static <T> T getBean(String name, Class<T> type){
		assertContextInjected();
	    return applicationContext.getBean(name, type);
	 }
	
	//和stringUtils类中的getMessage方法相同， 获得i18n字符串
	public static String getMessage(String code, Object[] args) {
		LocaleResolver localLocaleResolver = (LocaleResolver) applicationContext
				.getBean("localeResolver", LocaleResolver.class);
		Locale localLocale = localLocaleResolver.resolveLocale(null);
		return applicationContext.getMessage(code, args, localLocale);
	}

	/**
	 * 清除SpringContextHolder中的ApplicationContext为Null.
	 */
	public static void clearHolder() {
		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) {
		// logger.debug("注入ApplicationContext到SpringContextHolder:{}",
		// applicationContext);

		if (SpringContextHolder.applicationContext != null) {
			logger.warn("SpringContextHolder中的ApplicationContext被覆盖, 原有ApplicationContext为:"
					+ SpringContextHolder.applicationContext);
		}

		SpringContextHolder.applicationContext = applicationContext; // NOSONAR
	}

	/**
	 * 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.");
	}
}