1. 在配置檔案中加配置引數

#微信相關資料
wechat:
  mch_appid: abc122345677
  wx_secret: abcyyydffgdd7b95403552c2
  mchid: abc3asdfasd02
  key: Fasdf17Yasdfasd3asdf02
  url: https\://api.mch.weixin.qq.com/mmpaymkttransfers/promotion/transfers
  query_url: https\://api.mch.weixin.qq.com/mmpaymkttransfers/gettransferinfo
  sslFile: C:\\Users\\Administrator\\Desktop\\vym_doc\\20180116
 
wxpaycertificate\\cert\\apiclient_cert.p12
  app_access_token_url: https\://api.weixin.qq.com/cgi-bin/token?grant_type\=client_credential&appid\=abc122345677&secret\=abcyyydffgdd7b95403552c2
  template_id_msg: x9cUUj_pIabcyyydffgdd7b95403552c2aYArs

2. 在程式中呼叫

@Component
public class WechatAppAccessToken
 
 {
    private final static String ACCESS_TOKEN = "access_token";
    private final static String EXPIRES_IN = "expires_in";

    private static WechatAppAccessToken wechatAppAccessToken;
    @Resource
    private RedisUtil redisUtil;
    @Value("${wechat.app_access_token_url}")
    public String appTokenUrl; // WEB端的URL
 


    @PostConstruct
    public void init() {
        wechatAppAccessToken = this;
        wechatAppAccessToken.redisUtil = this.redisUtil;
        wechatAppAccessToken.appTokenUrl = this.appTokenUrl;
    }

    /**
     * 獲取微信公眾號的accessToken
     *            企業微信公眾號secret
     * @return
     * @throws Exception
     */
    @SuppressWarnings("unchecked")
    public static String getAppAccessToken(Boolean isValid) throws Exception {

        String accessTokenRds = wechatAppAccessToken.redisUtil.getValue(ACCESS_TOKEN+"_vym");
        if (!StringUtil.isEmpty(accessTokenRds, true) && accessTokenRds.length() > 20 && isValid)
            return accessTokenRds;
        else {
            String accessTokenStr = HttpClientUtil.sendJsonPost(wechatAppAccessToken.appTokenUrl, "");
            HashMap<String, Object> tokenMap = JsonUtil.json2bean(accessTokenStr, HashMap.class);
            accessTokenRds = (String) tokenMap.get(WechatAppAccessToken.ACCESS_TOKEN);
            if(StringUtil.isEmpty(accessTokenRds, true))
                return null;
            Integer expires_in = (Integer) tokenMap.get(WechatAppAccessToken.EXPIRES_IN);
            System.out.println("獲取新的token:" + accessTokenRds);
            wechatAppAccessToken.redisUtil.setRedisWithTime(ACCESS_TOKEN+"_vym",  accessTokenRds,expires_in);
            return accessTokenRds;
        }

    }
}

3. 分析

• 使用註解的時候，該類也必須要註解，否則不識別類內的註解
• 由於類內的載入順序問題，會預先載入靜態成員變數，導致無法獲取變數值。這時需要@PostConstruct來載入變數值。
• 雖然該類有註解，但是呼叫的時候，可以直接用靜態方法呼叫。
  

• String accessToken = WechatAppAccessToken.getAppAccessToken(true);