android端微信支付V3版本地签名统一下单详解

满满的都是坑，因为服务器偷懒让客服端写统一下单，服务器只给了通知的url。微信的支付demo并没有统一下单的代码。

读此文前先阅读： https://pay.weixin.qq.com/wiki/doc/api/app/app.PHP?chapter=9_1

一步步的来  先根据统一下单的参数介绍工具：

1. 获取到当前的ip：

<span style="font-size:14px;">public String getLocalIpAddress() {
    try {
      for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements(); ) {
        NetworkInterface intf = en.nextElement();
        for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements(); ) {
          InetAddress inetAddress = enumIpAddr.nextElement();
          if (!inetAddress.isLoopbackAddress()) {
            return inetAddress.getHostAddress().toString();
          }
        }
      }
    } catch (SocketException ex) {
    }
    return null;
  } 

  private String getWifiIp() {
    //获取wifi服务
    WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
    //判断wifi是否开启
    if (!wifiManager.isWifiEnabled()) {
      wifiManager.setWifiEnabled(true);
    }
    WifiInfo wifiInfo = wifiManager.getConnectionInfo();
    int ipAddress = wifiInfo.getIpAddress();
    String ip = intToIp(ipAddress);
    return ip;
  } 

  private String intToIp(int i) { 

    return (i & 0xFF) + "." +
        ((i >> 8) & 0xFF) + "." +
        ((i >> 16) & 0xFF) + "." +
        (i >> 24 & 0xFF);
  }
</span> 

2.随机订单号生成 test 你们可根据自己生成随机数：

<span style="font-size:14px;">private String genOutTradNo() {
    Random random = new Random();
    return MD5.getMessageDigest(String.valueOf(random.nextInt(10000)).getBytes());
  }</span> 

3.签名工具：

<span style="font-size:14px;">private String genAppSign(List<NameValuePair> params) {
    StringBuilder sb = new StringBuilder(); 

    for (int i = 0; i < params.size(); i++) {
      sb.append(params.get(i).getName());
      sb.append('=');
      sb.append(params.get(i).getValue());
      sb.append('&');
    }
    sb.append("key=");
    sb.append(Constants.API_KEY); 

    this.sb.append("sign str\n"+sb.toString()+"\n\n");
    String appSign = MD5.getMessageDigest(sb.toString().getBytes());
    Log.e("orion",appSign);
    return appSign;
  }</span> 

差不多了  现在我们需要生成传递的参数   参数要求是xml 格式的：

<span style="font-size:14px;">private String genProductArgs() {
    StringBuffer xml = new StringBuffer();
    String ip = getWifiIp();
    if (ip == "" && ip == "") {
      ip = getLocalIpAddress();
    }
    try {
      String nonceStr = genNonceStr();
      xml.append("</xml>");
      List<NameValuePair> packageParams = new LinkedList<NameValuePair>();
      packageParams.add(new BasicNameValuePair("appid", Constants.APP_ID));
      packageParams.add(new BasicNameValuePair("body", "APP pay test"));
      packageParams.add(new BasicNameValuePair("mch_id", Constants.MCH_ID));
      packageParams.add(new BasicNameValuePair("nonce_str", nonceStr));
      packageParams.add(new BasicNameValuePair("notify_url",ConfigUtil.NOTIFY_URL));
      packageParams.add(new BasicNameValuePair("out_trade_no",genOutTradNo()));
      packageParams.add(new BasicNameValuePair("spbill_create_ip",ip));
      packageParams.add(new BasicNameValuePair("total_fee", "1"));
      packageParams.add(new BasicNameValuePair("trade_type", "APP"));
      String sign = genPackageSign(packageParams);
      packageParams.add(new BasicNameValuePair("sign", sign));
      String xmlstring =toXml(packageParams);
      return xmlstring; 

    } catch (Exception e) {
      Log.e("TAG", "fail, ex = " + e.getMessage());
      return null;
    }
  }</span>

其中  toxml：

<span style="font-size:14px;">private String toXml(List<NameValuePair> params) {
    StringBuilder sb = new StringBuilder();
    sb.append("<xml>");
    for (int i = 0; i < params.size(); i++) {
      sb.append("<"+params.get(i).getName()+">"); 

      sb.append(params.get(i).getValue());
      sb.append("</"+params.get(i).getName()+">");
    }
    sb.append("</xml>"); 

    Log.e("orion",sb.toString());
    return sb.toString();
  }</span> 

得到传递的参数，根据文档指示，我们需要用post去吊连接URL地址：https://api.mch.weixin.qq.com/pay/unifiedorder：

<span style="font-size:14px;">  private class GetPrepayIdTask extends AsyncTask<Void, Void, Map<String,String>> { 

    private ProgressDialog dialog; 

    @Override
    protected void onPreExecute() {
      dialog = ProgressDialog.show(PayActivity.this, getString(R.string.app_tip), getString(R.string.getting_prepayid));
    } 

    @Override
    protected void onPostExecute(Map<String,String> result) {
      if (dialog != null) {
        dialog.dismiss();
      }
      sb.append("prepay_id\n"+result.get("prepay_id")+"\n\n"); 

      resultunifiedorder=result; 

    } 

    @Override
    protected void onCancelled() {
      super.onCancelled();
    } 

    @Override
    protected Map<String,String> doInBackground(Void... params) { 

      String url = String.format("https://api.mch.weixin.qq.com/pay/unifiedorder");
      String entity = genProductArgs(); 

      Log.e("orion",entity); 

      byte[] buf = Util.httpPost(url, entity); 

      String content = new String(buf);
      Log.e("orion", content);
      Map<String,String> xml=decodeXml(content); 

      return xml;
    }
  }</span>

其中decodexml就是：

 <span style="font-size:14px;">public Map<String,String> decodeXml(String content) { 

    try {
      Map<String, String> xml = new HashMap<String, String>();
      XmlPullParser parser = Xml.newPullParser();
      parser.setInput(new StringReader(content));
      int event = parser.getEventType();
      while (event != XmlPullParser.END_DOCUMENT) { 

        String nodeName=parser.getName();
        switch (event) {
          case XmlPullParser.START_DOCUMENT: 

            break;
          case XmlPullParser.START_TAG: 

            if("xml".equals(nodeName)==false){
              //实例化student对象
              xml.put(nodeName,parser.nextText());
            }
            break;
          case XmlPullParser.END_TAG:
            break;
        }
        event = parser.next();
      } 

      return xml;
    } catch (Exception e) {
      Log.e("orion",e.toString());
    }
    return null; 

  }</span>

下单完成，第二部就是给微信支付传递调起微信支付的参数（具体参数看文档说明）：

 <span style="font-size:14px;">private void genPayReq() { 

    req.appId = Constants.APP_ID;
    req.partnerId = Constants.MCH_ID;
    req.prepayId = resultunifiedorder.get("prepay_id");
    req.packageValue = "prepay_id="+resultunifiedorder.get("prepay_id");
    req.nonceStr = genNonceStr();
    req.timeStamp = String.valueOf(genTimeStamp());
    List<NameValuePair> signParams = new LinkedList<NameValuePair>();
    signParams.add(new BasicNameValuePair("appid", req.appId));
    signParams.add(new BasicNameValuePair("noncestr", req.nonceStr));
    signParams.add(new BasicNameValuePair("package", req.packageValue));
    signParams.add(new BasicNameValuePair("partnerid", req.partnerId));
    signParams.add(new BasicNameValuePair("prepayid", req.prepayId));
    signParams.add(new BasicNameValuePair("timestamp", req.timeStamp));
    req.sign = genAppSign(signParams);
    sb.append("sign\n"+req.sign+"\n\n"); 

    Log.e("orion", signParams.toString()); 

  }</span>

第三部，调微信支付：

 <span style="font-size:14px;">private void sendPayReq() {
    msgApi.registerApp(Constants.APP_ID);
    msgApi.sendReq(req);
  }</span>

其中：

 <span style="font-size:14px;">Constants.APP_ID</span>

是appid 在开发者平台获取

<span style="font-size:14px;">    req.partnerId = Constants.MCH_ID;</span> 

商户id

<span style="font-size:14px;">ConfigUtil.NOTIFY_URL</span> 

支付后的回调通知地址。

签名两次，然后用的api——key是商户平台api安全里面自定义的。

对了 还有个获取时间工具

<span style="font-size:14px;">private long genTimeStamp() {
    return System.currentTimeMillis() / 1000;
  }</span>

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。