/**
 * 应用完全启动后, Spring执行自定义初始化 此处初始化避免了初始化static时 bean还没注入的问题
 */
spirng mvc xml 文件
<!-- spring环境都初始化完成后执行的一些操作 -->
<bean id="instantiationListener" class ="com.xxx.xxx.web.base.InstantiationListener" />



import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;

/**
 * 应用完全启动后, Spring执行自定义初始化 此处初始化避免了初始化static时 bean还没注入的问题
 */
public class InstantiationListener implements InitializingBean {
	
    private static final Logger logger = LoggerFactory.getLogger(InstantiationListener.class);
	@Autowired
	private WechatAccessTokenService wechatAccessTokenService;// 这里注入不会有生存周期的问题
	

	
	// ==>继承于InitializingBean 的afterPropertiesSet()方法是初始化方法.
	@Override
	public void afterPropertiesSet() {
		try {
			System.out.println("init.....初始化微信获取accessToken service....");
			JwTokenAPI.wechatAccessTokenService = wechatAccessTokenService; //JwTokenAPI类的静态属性是wechatAccessTokenService
		} catch (Exception e) {
			logger.error("初始化微信获取accessToken service [wechatAccessTokenService] 异常");
		}
	}
}

	/**
	 * 功能：将http://example.com重定向至http://www.example.com
	 * */
	private static final String DOMAIN = "aaa.com";

	/**
	 * 在DispatcherServlet之前执行
	 * */
	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, 
			Object handler) throws Exception {

		HttpServletRequest httpServletRequest = (HttpServletRequest) request;
		HttpServletResponse httpServletResponse = (HttpServletResponse) response;
		// 获取域名
		String serverName = request.getServerName();
		// 获取请求路径
		String path = httpServletRequest.getRequestURI();
		//queryString 支持多参数 ?a=1&b=2#&c=22## 等
		String queryString = (httpServletRequest.getQueryString() == null ? "" : "?"+httpServletRequest.getQueryString());   // 获取路径中的参数
		int end = serverName.indexOf(DOMAIN);
		if (end!= -1 && end == 0) {  //判断是否是example.com，如果是通过ip地址访问暂时不处理 //end == -1 || end == 0（不是本域名都跳转）
			httpServletResponse.setStatus(301);
			httpServletResponse.setHeader( "Location", "http://www."+DOMAIN+path+queryString);
			httpServletResponse.setHeader( "Connection", "close" );
			return false;
		}


		return true;
	}