Android实现微信支付的统一下单

dependencies {
 compile 'com.tencent.mm.opensdk:wechat-sdk-android-with-mta:+'
}

dependencies {
 compile 'com.tencent.mm.opensdk:wechat-sdk-android-without-mta:+'
}

//拼接字段，顺序不能变
    String A = "appid=你的appID" +
      "&body=jinshi" +
      "&mch_id=你的商户号" +
      "&nonce_str=" + nonce_str +
      "¬ify_url=http://www.szgsip.com/" +
      "&out_trade_no=" + trade_no +
      "&spbill_create_ip=192.168.1.1" +
      "&total_fee=1" +
      "&trade_type=APP";
    String key = "你的密钥";
    String temp = A + "&key=" + key;
 // 生成sign
     String sign = MD5.getMessageDigest(temp.getBytes()).toUpperCase();

 private void httpThreadxml() {


  //组建xml数据
  //拼接字段，顺序不能变

  xml.append("\n");
    xml.append("你的appID\n");
    xml.append("jinshi\n");
    xml.append("你的商户号\n");
    xml.append("" + nonce_str + "\n");
    xml.append("http://www.szgsip.com/\n");
    xml.append("" + trade_no + "\n");
    xml.append("192.168.1.1\n");
    xml.append("1\n");
    xml.append("APP\n");
    xml.append("" + sign + "\n");
    xml.append("");

  try {
   final byte[] xmlbyte = xml.toString().getBytes("UTF-8");

   System.out.println(xml);

   URL url = new URL("https://api.mch.weixin.qq.com/pay/unifiedorder");


   final HttpURLConnection cOnn= (HttpURLConnection) url.openConnection();
   conn.setConnectTimeout(5000);
   conn.setDoOutput(true);// 允许输出
   conn.setDoInput(true);
   conn.setUseCaches(false);// 不使用缓存
   conn.setRequestMethod("POST");
   conn.setRequestProperty("Connection", "Keep-Alive");// 维持长连接
   conn.setRequestProperty("Charset", "UTF-8");
   conn.setRequestProperty("Content-Length",
     String.valueOf(xmlbyte.length));
   conn.setRequestProperty("Content-Type", "text/xml; charset=UTF-8");
   conn.setRequestProperty("X-ClientType", "2");//发送自定义的头信息


   conn.getOutputStream().write(xmlbyte);
   conn.getOutputStream().flush();
   conn.getOutputStream().close();


   if (conn.getResponseCode() != 200)
    throw new RuntimeException("请求url失败");

   InputStream is = conn.getInputStream();// 获取返回数据


   // 使用输出流来输出字符(可选)
   ByteArrayOutputStream out = new ByteArrayOutputStream();
   byte[] buf = new byte[1024];
   int len;
   while ((len = is.read(buf)) != -1) {
    out.write(buf, 0, len);
   }
   String string = out.toString("UTF-8");
   System.out.println(string);

   Log.e("  微信返回数据 ", " --- " + string);
   out.close();


  } catch (Exception e) {

   System.out.println(e);
  }
}

new Thread(new Runnable() {
    @Override
    public void run() {
     httpThreadxml();
   }
 }).start();