[051] 微信公众平台开发教程第22篇-如何保证access

package org.liufeng.weixin.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import org.liufeng.weixin.thread.TokenThread;
import org.liufeng.weixin.util.WeixinUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 初始化servlet
 * 
 * @author liuyq
 * @date 2013-05-02
 */
public class InitServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private static Logger log = LoggerFactory.getLogger(WeixinUtil.class);

	public void init() throws ServletException {
		// 获取web.xml中配置的参数
		TokenThread.appid = getInitParameter("appid");
		TokenThread.appsecret = getInitParameter("appsecret");

		log.info("weixin api appid:{}", TokenThread.appid);
		log.info("weixin api appsecret:{}", TokenThread.appsecret);

		// 未配置appid、appsecret时给出提示
		if ("".equals(TokenThread.appid) || "".equals(TokenThread.appsecret)) {
			log.error("appid and appsecret configuration error, please check carefully.");
		} else {
			// 启动定时获取access_token的线程
			new Thread(new TokenThread()).start();
		}
	}
}

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemalocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

	<servlet>
		<servlet-name>initServlet</servlet-name>
		<servlet-class>
			org.liufeng.weixin.servlet.InitServlet
		</servlet-class>
		<!-- 配置获取access_token所需参数appid和appsecret -->
		<init-param>
			<param-name>appid</param-name>
			<param-value>wx617a123bb8bc99cd</param-value>
		</init-param>
		<init-param>
			<param-name>appsecret</param-name>
			<param-value>4d82cbbbb08714c12345b62d7hn3dcb8</param-value>
		</init-param>
		<load-on-startup>0</load-on-startup>
	</servlet>

	<welcome-file-list>
		<welcome-file>index.jsp</welcome-file>
	</welcome-file-list>
</web-app>

package org.liufeng.weixin.thread;

import org.liufeng.weixin.pojo.AccessToken;
import org.liufeng.weixin.util.WeixinUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 定时获取微信access_token的线程
 * 
 * @author liuyq
 * @date 2013-05-02
 */
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 = "";
	public static AccessToken accessToken = null;

	public void run() {
		while (true) {
			try {
				accessToken = WeixinUtil.getAccessToken(appid, appsecret);
				if (null != accessToken) {
					log.info("获取access_token成功，有效时长{}秒 token:{}", accessToken.getExpiresIn(), accessToken.getToken());
					// 休眠7000秒
					Thread.sleep((accessToken.getExpiresIn() - 200) * 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);
			}
		}
	}
}

[INFO ] weixin api appid:wx617a123bb8bc99cd
[INFO ] weixin api appsecret:4d82cbbbb08714c12345b62d7hn3dcb8
[INFO ] 获取access_token成功，有效时长7200秒 token:sFopJ9lMmLl4u-ad61ojKpS0TolhN2s3SnHoI2Mh5GgdiYb35i-7DG2T2CDyQKMe