Android微信支付功能集成【全攻略】

比眉伴天荒 2022-07-15 01:42 388阅读 0赞

## ![Center][]     遵循：[BY-SA][]  [署名-相同方式共享 4.0协议][BY-SA] ##

作者：谭东

时间：2016年10月28日

环境：Windows 7

Android版微信支付官方文档和Demo问题很多，官方也没有及时更新和细化开发集成文档。

这里分享我集成Android客户端微信支付的思路和部分代码。希望对大家有帮助。

遇到的问题无非以下几种：

1、提示签名不对；

2、打包签名后的APK无法调起微信支付客户端，直接返回回调页；

3、不支持中文的Body；

4、支付的钱倍数不对，因为微信的单位是分；

... ...

首先，本文针对的是最新版微信Android支付SDK3.1.1写的，大家可以放心使用。

首先，把WXPayEntryActivity.java复制到我们的包名下的.wxapi目录下，要一致。

WXPayEntryActivity.java官方Demo里有，我这里也复制一份我的，仅供参考。

public class WXPayEntryActivity extends BaseActivity implements IWXAPIEventHandler {
        private IWXAPI api;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            api = WXAPIFactory.createWXAPI(this, Conf.APP_ID);
            api.handleIntent(getIntent(), this);
            getSupportActionBar().setIcon(R.drawable.logo_gray);
            getSupportActionBar().setTitle("购买积分");
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            Drawable dw = getResources().getDrawable(R.drawable.color_bg);
            getSupportActionBar().setBackgroundDrawable(dw);
        }
    
        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            if (item.getItemId() == android.R.id.home) {
                this.finish();
            }
            return super.onOptionsItemSelected(item);
        }
    
        @Override
        protected void onNewIntent(Intent intent) {
            super.onNewIntent(intent);
            setIntent(intent);
            api.handleIntent(intent, this);
        }
    
        @Override
        public void onReq(BaseReq baseReq) {
        }
    
        @Override
        public void onResp(BaseResp baseResp) {
            if (baseResp.getType() == ConstantsAPI.COMMAND_PAY_BY_WX) {
                Log.d("info", "onPayFinish,errCode=" + baseResp.errCode);
                if (baseResp.errCode == 0) {
                    ToastUtil.showToast(this, "支付成功");
                    Intent intent = new Intent("ACTION_PAY");
                    sendBroadcast(intent);
                    this.finish();
                } else if (baseResp.errCode == -1) {
                    ToastUtil.showToast(this, "配置错误");
                    this.finish();
                } else if (baseResp.errCode == -2) {
                    ToastUtil.showToast(this, "用户取消");
                    this.finish();
                }
            } else {
                ToastUtil.showToast(this, baseResp.errStr);
            }
        }
    }

这里说一下Android微信支付流程，这里本地客户端都处理了所有的流程。

客户端把所有需要的信息拼接为XML后，统一下单，发送给微信服务器API请求，获取订单id，也就是prepayId。获取到这个prepayId后，我们再把必要的数据字段sign签名MD5后，调起微信支付客户端就可以了。比支付宝麻烦很多。

1、在程序的启动页，例如欢迎页就可以注册微信API的ID了。

IWXAPI msgApi = WXAPIFactory.createWXAPI(this, Conf.APP_ID);
            msgApi.registerApp(Conf.APP_ID);

完毕。

2、接下来处理微信POST请求的必要参数的拼接和加密等处理。写PayActivity.java

统一下单获取prepayId的接口地址：[https://api.mch.weixin.qq.com/pay/unifiedorder][https_api.mch.weixin.qq.com_pay_unifiedorder]

微信文档地址：[https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=9\_1][https_pay.weixin.qq.com_wiki_doc_api_app_app.php_chapter_9_1]

把必填的参数处理下：

nonce\_str：随机字符串，不长于32位。

out\_trade\_no：商户系统内部的订单号，32个字符内、可包含字母。

spbill\_create\_ip：用户端实际ip，16位，可写固定值。

notify\_url：暂时写成固定的，http://www.weixin.qq.com/wxpay/pay.php。

最麻烦的，sign：32位签名，参照[签名生成算法][Link 1]。

以上这些算法我都会写成工具类，供大家参考。

签名算法：

![Center 1][]

附上整个支付代码：

PayActivity.java里关于支付的代码：

private IWXAPI api;
        private String stringA;
        private String noneString;
        private String out_trade_no;
        private String sign;
        private String prepayId;
        private String ip;
        private String body = "商品-积分充值";
        private static final String order_url = "https://api.mch.weixin.qq.com/pay/unifiedorder";//POST请求统一下单接口地址
        private String notify_url = "http://www.weixin.qq.com/wxpay/pay.php";
        private String entity;//XML形式的post请求实体
    
        private void payWeixin(int money) {
            api = WXAPIFactory.createWXAPI(this, Conf.APP_ID);
            try {
                body = new String(body.getBytes(), "utf-8");
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            noneString = Utils.createRandomString(true, 32);//32位随机字符串
            out_trade_no = Utils.createRandomString(true, 20) + Utils.timeStamp();//30位内部随机订单号
            ip = "123.123.123.123";
            stringA = "appid=" + Conf.APP_ID + "&body=" + body + "&mch_id=" + Conf.MCH_ID + "&nonce_str=" + noneString + "¬ify_url=" + notify_url + "&out_trade_no=" + out_trade_no + "&spbill_create_ip=" + ip + "&" +
                    "total_fee=" + money + "&trade_type=APP";
            String stringSignTemp = stringA + "&key=" + Conf.KEY;
            sign = Utils.getMD5(stringSignTemp).toUpperCase(Locale.getDefault());
    
            entity = "<xml><appid>" + Conf.APP_ID + "</appid><mch_id>" + Conf.MCH_ID + "</mch_id><nonce_str>" + noneString + "</nonce_str><sign>" + sign +
                    "</sign><body>" + body + "</body><out_trade_no>" + out_trade_no + "</out_trade_no><total_fee>" + money +
                    "</total_fee><spbill_create_ip>" + ip + "</spbill_create_ip><notify_url>" + notify_url + "</notify_url><trade_type>APP</trade_type></xml>";
    
            try {
                entity = new String(entity.getBytes(), "ISO8859-1");//想要支持中文的Boby，那就要把XML转码为ISO8859-1即可
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
    
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        byte[] buf = Utils.httpPost(order_url, entity);
                        Message message = new Message();
                        message.what = 0;
                        message.obj = buf;
                        handler.sendMessage(message);
                    } catch (Exception e) {
                        Log.e("info", "异常：" + e.getMessage());
                    }
                }
            }).start();
        }
    
        Handler handler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                super.handleMessage(msg);
                switch (msg.what) {
                    case 0:
                        byte[] buf = (byte[]) msg.obj;
                        if (buf != null && buf.length > 0) {
                            String content = new String(buf);
                            OrderResult orderResult = Tools.parseXml(new ByteArrayInputStream(content.getBytes()));
                            if (!TextUtils.equals(orderResult.getReturnCode(), "SUCCESS")) {
                                Toast.makeText(PayActivity.this, orderResult.getReturnMsg(), Toast.LENGTH_SHORT).show();
                                return;
                            }
                            if (!TextUtils.equals(orderResult.getResultCode(), "SUCCESS")) {
                                Toast.makeText(PayActivity.this, orderResult.getErrorDesc(), Toast.LENGTH_SHORT).show();
                                return;
                            }
                            PayReq req = new PayReq();
                            req.appId = Conf.APP_ID;
                            req.partnerId = Conf.MCH_ID;
                            req.prepayId = orderResult.getPrepayId();
                            req.packageValue = "Sign=WXPay";
                            req.nonceStr = noneString;
                            String timeStamp = Utils.timeStamp();
                            req.timeStamp = timeStamp;
                            req.sign = Utils.getMD5("appid=" + Conf.APP_ID + "&noncestr=" + noneString + "&package=Sign=WXPay" +
                                    "&partnerid=" + Conf.MCH_ID + "&prepayid=" + orderResult.getPrepayId() + "×tamp=" + timeStamp + "&key=" + Conf.KEY).toUpperCase(Locale.getDefault());
                            api.sendReq(req);
                        } else {
                            Log.d("PAY_GET", "服务器请求错误");
                            Toast.makeText(PayActivity.this, "服务器请求错误", Toast.LENGTH_SHORT).show();
                        }
                        break;
                }
            }
        };

Utils工具类代码：

public class Utils {
    
        /**
         * 产生随机字符串
         *
         * @param numberFlag 是否允许有字母
         * @param length     随机字符串长度
         * @return 随机字符串
         */
        public static String createRandomString(boolean numberFlag, int length) {
            String retStr = "";
            String strTable = numberFlag ? "1234567890" : "1234567890abcdefghijkmnpqrstuvwxyz";
            int len = strTable.length();
            boolean bDone = true;
            do {
                retStr = "";
                int count = 0;
                for (int i = 0; i < length; i++) {
                    double dblR = Math.random() * len;
                    int intR = (int) Math.floor(dblR);
                    char c = strTable.charAt(intR);
                    if (('0' <= c) && (c <= '9')) {
                        count++;
                    }
                    retStr += strTable.charAt(intR);
                }
                if (count >= 2) {
                    bDone = false;
                }
            } while (bDone);
    
            return retStr;
        }
    
        /**
         * 获取MD5加密后的字符串
         *
         * @param val 待加密字符串
         * @return 加密后字符串
         */
        public static String getMD5(String val) {
            byte[] m = new byte[0];
            try {
                MessageDigest md5 = MessageDigest.getInstance("MD5");
                md5.update(val.getBytes());
                m = md5.digest();
            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            }
            return getString(m);
        }
    
        private static String getString(byte[] b) {
            StringBuffer sb = new StringBuffer();
            for (int i = 0; i < b.length; i++) {
                sb.append(b[i]);
            }
            return sb.toString();
        }
    
        /**
         * 获取10位长度的时间戳
         *
         * @return 10位时间戳
         */
        public static String timeStamp() {
            String time = String.valueOf(System.currentTimeMillis());
            return time.substring(0, 10);
        }
    
    
        public static byte[] httpGet(final String url) {
            if (url == null || url.length() == 0) {
                return null;
            }
            HttpClient httpClient = getNewHttpClient();
            HttpGet httpGet = new HttpGet(url);
            try {
                HttpResponse resp = httpClient.execute(httpGet);
                if (resp.getStatusLine().getStatusCode() != HttpStatus.SC_OK) {
                    return null;
                }
                return EntityUtils.toByteArray(resp.getEntity());
    
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    
        public static byte[] httpPost(String url, String entity) {
            if (url == null || url.length() == 0) {
                return null;
            }
            HttpClient httpClient = getNewHttpClient();
            HttpPost httpPost = new HttpPost(url);
            try {
                httpPost.setEntity(new StringEntity(entity));
                httpPost.setHeader("Accept", "application/json");
                httpPost.setHeader("Content-type", "application/json");
                HttpResponse resp = httpClient.execute(httpPost);
                if (resp.getStatusLine().getStatusCode() != HttpStatus.SC_OK) {
                    return null;
                }
                return EntityUtils.toByteArray(resp.getEntity());
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    
        private static HttpClient getNewHttpClient() {
            try {
                KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
                trustStore.load(null, null);
    
                SSLSocketFactory sf = new SSLSocketFactoryEx(trustStore);
                sf.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
    
                HttpParams params = new BasicHttpParams();
                HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
                HttpProtocolParams.setContentCharset(params, HTTP.UTF_8);
    
                SchemeRegistry registry = new SchemeRegistry();
                registry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
                registry.register(new Scheme("https", sf, 443));
    
                ClientConnectionManager ccm = new ThreadSafeClientConnManager(params, registry);
    
                return new DefaultHttpClient(ccm, params);
            } catch (Exception e) {
                return new DefaultHttpClient();
            }
        }
    
        public static OrderResult parseXml(InputStream is) {
            XmlPullParser parser = Xml.newPullParser();
            OrderResult orderResult = null;
            try {
                parser.setInput(is, "UTF-8");
                int type = parser.getEventType();
                while (type != XmlPullParser.END_DOCUMENT) {
                    switch (type) {
                        case XmlPullParser.START_DOCUMENT:
                            break;
                        case XmlPullParser.START_TAG:
                            if (parser.getName().equals("xml")) {
                                orderResult = new OrderResult();
                            } else if (parser.getName().equals("return_code")) {
                                orderResult.setReturnCode(parser.nextText());
                            } else if (parser.getName().equals("return_msg")) {
                                orderResult.setReturnMsg(parser.nextText());
                            } else if (parser.getName().equals("result_code")) {
                                orderResult.setResultCode(parser.nextText());
                            } else if (parser.getName().equals("err_code_des")) {
                                orderResult.setErrorDesc(parser.nextText());
                            } else if (parser.getName().equals("prepay_id")) {
                                orderResult.setPrepayId(parser.nextText());
                            } else if (parser.getName().equals("sign")) {
                                orderResult.setSign(parser.nextText());
                            }
                            break;
                        case XmlPullParser.END_TAG:
                            break;
                    }
    
                    type = parser.next();
                }
            } catch (XmlPullParserException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return orderResult;
        }
    }

这样整个微信Android支付集成就完毕了。

[Center]: /images/20220715/b488865b00e64caeb249c4416f9ddc0d.png
[BY-SA]: https://creativecommons.org/licenses/by-sa/4.0/
[https_api.mch.weixin.qq.com_pay_unifiedorder]: https://api.mch.weixin.qq.com/pay/unifiedorder
[https_pay.weixin.qq.com_wiki_doc_api_app_app.php_chapter_9_1]: https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=9_1
[Link 1]: https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=4_3
[Center 1]: /images/20220715/b5a1458c29c64155990f07feedc8b7e6.png