微信开发如何保证access_token/jsapi_ticket长期有效

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 初始化servlet
 * 用 TokenThread.token 来得到接口访问凭证access_toke
 */
public class InitServlet extends HttpServlet {
	
	private static final long serialVersionUID = 1L;
	private static Logger log = LoggerFactory.getLogger(InitServlet.class);

	public void init() throws ServletException {
		// 获取web.xml中配置的参数
		TokenThread.appid = Wx_appId;
		TokenThread.appsecret = Wx_appsecret;
		
		log.info("微信appid:{}", TokenThread.appid);
		log.info("微信appsecret:{}", TokenThread.appsecret);

		// 未配置appid、appsecret时给出提示
		if ("".equals(TokenThread.appid) || "".equals(TokenThread.appsecret)) {
			log.error("appid 或 appsecret 配置为空,请仔细核对！");
		} else {
			// 启动定时获取access_token的线程
			new Thread(new TokenThread()).start();
		}
	}
}

<!-- access token缓存  -->
  <servlet>  
        <servlet-name>initServlet</servlet-name>
        <servlet-class>com.nit.support.utils.wechat.InitServlet</servlet-class>
        <load-on-startup>0</load-on-startup>
    </servlet>

import java.util.concurrent.ConcurrentHashMap;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.test.utils.wechat.pojo.Token;

/**
 * 定时获取微信access_token的线程
 * 用 TokenThread.token 来得到接口访问凭证access_toke
 */
public class TokenThread implements Runnable {
	private static Logger log = LoggerFactory.getLogger(TokenThread.class);
	// 第三方用户唯一凭证
	public static String appid = "";
	// 第三方用户唯一凭证密钥
	public static String appsecret = "";
	// token
	public static Token accessToken = null;
	// jsapi_ticket
	public static String jsapi_ticket = null;
	
	public static ConcurrentHashMap<String, Token> token = new ConcurrentHashMap<>();
	public static ConcurrentHashMap<String, String> ticket = new ConcurrentHashMap<>();

	public void run() {
		while (true) {
			try {
				accessToken = CommonUtil.getToken(appid, appsecret);
				
				token.put(appid, accessToken);
				
				if (null != accessToken) {
					log.info("获取access_token成功，有效时长{}秒 token:{}", accessToken.getExpiresIn(), accessToken.getAccessToken());
					jsapi_ticket = CommonUtil.getJsApiTicket(accessToken.getAccessToken());
					
					ticket.put(appid, jsapi_ticket);
					
					if(null != jsapi_ticket) {
						log.info("获取jsapi_ticket成功， jsapi_ticket:{}", jsapi_ticket);
						// 休眠7000秒
						Thread.sleep((accessToken.getExpiresIn() - 200) * 1000);
						//Thread.sleep(60 * 1000);//测试休眠1分钟
					}
					else{
						// 如果jsapi_ticket为null，60秒后再获取
						Thread.sleep(60 * 1000);
					}
				} else {
					// 如果access_token为null，60秒后再获取
					Thread.sleep(60 * 1000);
				}
			} catch (InterruptedException e) {
				try {
					Thread.sleep(60 * 1000);
				} catch (InterruptedException e1) {
					log.error("{}", e1);
				}
				log.error("{}", e);
			}
		}
	}
}