@GetMapping("get")
    @ApiOperation(value = "微信公眾號驗(yàn)證接口")
    public String init(String signature,String timestamp,String nonce,String echostr) throws NoSuchAlgorithmException {
        String token = "test";
        List<String> stringList = Arrays.asList(token, timestamp, nonce);
        Collections.sort(stringList);
        StringBuilder stringBuilder=new StringBuilder();
        for (String s : stringList) {
            stringBuilder.append(s);
        }
        MessageDigest sha1 = MessageDigest.getInstance("sha1");
        byte[] bytes = sha1.digest(stringBuilder.toString().getBytes());
        StringBuilder sum=new StringBuilder();
        for (byte aByte : bytes) {
            sum.append(Integer.toHexString(((aByte>>4)&15)));
            sum.append(Integer.toHexString(aByte&15));
        }
        if (signature!=null&&signature.equals(sum.toString())){
            return echostr;
        }
        return echostr;
    }

 private static AccessToken getToken() throws IOException {
        String url=String.
                format("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=%s&secret=%s",appid,secret);
        String st = HttpRestUtils.get(url, null);
        JSONObject jsonObject=new JSONObject(st);
        String access_token = jsonObject.getStr("access_token");
        Long expires_in = jsonObject.getLong("expires_in");
        accessToken.setToken(access_token);
        accessToken.setExpiresTime(expires_in);
        return accessToken;
    }

    public static String getAccessToken() throws IOException {
        if (accessToken!=null || accessToken.isExpires()){
            getToken();
        }
        return accessToken.getToken();
    }