(转载)安卓项目集成微信支付

         开发Android APP微信支付功能，需要完成三个步骤：第一步生成预支付订单、第二步生成微信支付参数、第三步调起微信APP支付。除了需要审核通过的APP应用外，还需要获得微信支付接口权限，然后获取对应的商户号、API密钥，这两者缺一不可，并且在APP微信支付中使用

获得商户号、API密钥

在微信开放平台中查看审核通过的APP应用，是否申请支付功能，若已申请，登录微信支付|商户平台：http://pay.weixin.qq.com 查看对应的商户号、API密钥

》申请微信支付接口

》登录商户平台

》查看商户号

》获取API密钥

代码部分

第一步：生成预支付订单

将商品信息、商户信息使用BasicNameValuePair存放，然后存储在List列表中，并构造成xml字符串格式，以POST方式微信提供的接口：https://api.mch.weixin.qq.com/pay/unifiedorder 发送数据，接收返回信息，获取prepay_id预支付订单编号

》生成订单请求

private String genProductArgs() {StringBuffer xml = new StringBuffer();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", "weixin"));packageParams.add(new BasicNameValuePair("mch_id", Constants.MCH_ID));packageParams.add(new BasicNameValuePair("nonce_str", nonceStr));packageParams.add(new BasicNameValuePair("notify_url","http://121.40.35.3/test"));packageParams.add(new BasicNameValuePair("out_trade_no",genOutTradNo()));packageParams.add(new BasicNameValuePair("spbill_create_ip","127.0.0.1"));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, "genProductArgs fail, ex = " + e.getMessage());return null;}}

》获取预支付订单编号

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);

第二步：生成微信支付参数

appId对应APP应用的APPID，partnerId对应商户号，prepayId对应第一步获得的预支付订单，packageValue取值Sign=WXPay，nonceStr是一串随机数，timeStamp生成的时间戳，sign对应APP签名

》支付参数配置

private void genPayReq() {req.appId = Constants.APP_ID;req.partnerId = Constants.MCH_ID;req.prepayId = resultunifiedorder.get("prepay_id");req.packageValue = "Sign=WXPay";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");show.setText(sb.toString());Log.e("orion", signParams.toString());}

》nonceStr随机数

private String genNonceStr() {Random random = new Random();return MD5.getMessageDigest(String.valueOf(random.nextInt(10000)).getBytes());}

》timeStamp时间戳

<pre name="code" class="java">private long genTimeStamp() {return System.currentTimeMillis() / 1000;}

》APP签名

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()).toUpperCase();Log.e("orion", appSign);return appSign;}

第三步：调起微信APP支付

支付之前，需要手机安装微信客户端，如果没有，会提示下载安装微信，然后再调起支付，在AndroidManifest.xml文件中添加如下配置

  <activity        android:name=".act.PayActivity"        android:exported="true"        android:launchMode="singleTop" >        <intent-filter>            <action android:name="android.intent.action.VIEW" />            <category android:name="android.intent.category.DEFAULT" />            <data android:scheme="wxf2f565574a968187" />        </intent-filter>    </activity>

》调起微信支付

private void sendPayReq() {msgApi.registerApp(Constants.APP_ID);msgApi.sendReq(req);}

接收微信返回结果

在实现了IWXAPIEventHandler接口的Activity中重写onResp(BaseResp)方法，接收微信结果

》接收支付结果

public void onResp(BaseResp resp) {Log.d(TAG, "onPayFinish, errCode = " + resp.errCode);if (resp.getType() == ConstantsAPI.COMMAND_PAY_BY_WX) {AlertDialog.Builder builder = new AlertDialog.Builder(this);builder.setTitle(R.string.app_tip);builder.setMessage(getString(R.string.pay_result_callback_msg,resp.errStr + ";code=" + String.valueOf(resp.errCode)));builder.show();}}