微信公众号JSSDK获取signature签名

 

1、获取微信公众号signature需要有三个参数 ----  appId 、appsecret 、 url

appId 和 appsecret 只需登录“微信公众平台”--“开发”--“基本设置”

url则是前台传过来的当前页面的地址值

2、获取微信公众号signature需要先获取三个参数 noncestr、timestamp、jsapi_ticket，以及上面的url值

由这四个参数组合后进行加密，便是signature

其中noncestr、timestamp获取很简单，只是单纯的获取随机数和时间戳

而jsapi_ticket则先需获取access_token，在获取access_token过程中就会用到上面的appId 、appsecret

获取到的jsapi_ticket以及access_token是有时间限制的，正常为7200秒，需注意！！！

粗略讲解到此结束！！！

 

 一、先获取access_token

public String getAccessToken(String appId , String appSecret){
    // 网页授权接口
    String GetPageAccessTokenUrl = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid="+appId+"&secret="+appSecret;

    HttpClient client = null;
    String access_token = null;
    int expires_in = 0;
    try {
        client = new DefaultHttpClient();
        HttpGet httpget = new HttpGet(GetPageAccessTokenUrl);
        ResponseHandler responseHandler = new BasicResponseHandler();
        String response = client.execute(httpget, responseHandler);
        JSONObject OpenidJSONO = JSONObject.fromObject(response);
        access_token = String.valueOf(OpenidJSONO.get("access_token"));//获取access_token 
        expires_in = Integer.parseInt(String.valueOf(OpenidJSONO.get("expires_in")));//获取时间
    } catch (Exception e) {
        throw new CommonRuntimeException("获取AccessToken出错！");
    } finally {
        client.getConnectionManager().shutdown();
    }
    return access_token;
}

 

二、获取jsapi_ticket

public String getTicket(String accessToken) {
    // 网页授权接口
   String GetPageAccessTokenUrl = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token="+accessToken+"&type=jsapi";
    HttpClient client = null;
    String ticket = "";
    int expires_in = 0;
    try {
        client = new DefaultHttpClient();
        HttpGet httpget = new HttpGet(GetPageAccessTokenUrl);
        ResponseHandler responseHandler = new BasicResponseHandler();
        String response = client.execute(httpget, responseHandler);
        JSONObject OpenidJSONO = JSONObject.fromObject(response);
        ticket = String.valueOf(OpenidJSONO.get("ticket"));//获取ticket
        expires_in = Integer.parseInt(String.valueOf(OpenidJSONO.get("expires_in")));//获取时间
    } catch (Exception e) {
        throw new CommonRuntimeException("获取Ticket出错！");
    } finally {
        client.getConnectionManager().shutdown();
    }

    return ticket;
}

 

三、SHA1加密，参数是由url、jsapi_ticket、noncestr、timestamp组合而成

public String SHA1(String str) {
    try {
        MessageDigest digest = java.security.MessageDigest
                .getInstance("SHA-1"); //如果是SHA加密只需要将"SHA-1"改成"SHA"即可
        digest.update(str.getBytes());
        byte messageDigest[] = digest.digest();
        // Create Hex String
        StringBuffer hexStr = new StringBuffer();
        // 字节数组转换为 十六进制 数
        for (int i = 0; i < messageDigest.length; i++) {
            String shaHex = Integer.toHexString(messageDigest[i] & 0xFF);
            if (shaHex.length() < 2) {
                hexStr.append(0);
            }
            hexStr.append(shaHex);
        }
        return hexStr.toString();

    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
    }
    return null;
}

 

四、获取 Signature

public String getSignature(String url) {

    String signature = "";

    String appid = *********;//微信公众号的appid
    String appsecret = ***********;//微信公众号的appsecret

    //获取noncestr
    String noncestr = UUID.randomUUID().toString();
    //获取timestamp
    String timestamp = Long.toString(System.currentTimeMillis() / 1000);
    //获取access_token
    String access_token = getAccessToken(appid , appsecret);
    //获取jspai_ticket
    String jsapi_ticket = getTicket(access_token);
    //将四个数据进行组合，传给SHA1进行加密
    String str = "jsapi_ticket=" + jsapi_ticket +
            "&noncestr=" + noncestr +
            "×tamp=" + timestamp +
            "&url=" + url;

    //sha1加密
    signature = SHA1(str);

    return signature ;
}

 经过上方四个步骤就可以获得signature了，但在我自己实现的过程中，遇到了一个问题，在此提醒一下

若appid、appsecret使用的是企业微信公众号，则会在获取access_token、jsapi_ticket中取得null值

报了IP地址不在于白名单中，我采取了使用个人微信公众号的解决方法，则可以正常使用。