Android接入微信支付的方法

final IWXAPI msgApi = WXAPIFactory.createWXAPI(context, null);// 将该app注册到微信msgApi.registerApp("wxd930ea5d5a258f4f");

        String url = "https://api.mch.weixin.qq.com/pay/unifiedorder";        WXPrePost post = new WXPrePost();        post.appid = "你的appId";        post.mch_id = "你的商户号";        post.nonce_str = StringUtils.genNonceStr();//随机字符串 **1        post.body = "商品名称";        post.detail = "商品的描述";        post.out_trade_no = out_trade_no; //商户订单号 **2        post.total_fee = "商品价格";//单位是分        post.spbill_create_ip = getLocalIpAddress();//ip地址 **3        post.notify_url = "";//这里是后台接受支付结果通知的url地址        post.trade_type = "APP";        post.sign = genPackageSign(post);//签名 **4        List<NameValuePair> firstSignParams = getFirstSignParams(post);        String xml = toXml(firstSignParams);        String entity = null;        try {          entity = new String(xml.getBytes(), "ISO8859-1");          byte[] buf = Util.httpPost(url, entity);          if (buf != null) {            String content = new String(buf);            Map<String, String> map = decodeXml(content);            if (map != null) {              //再次签名(参与签名的字段有 :Appid partnerId prepayId nonceStr TimeStamp package)              String appId = "";              String prepayId = "";              String nonceStr = "";              for (Map.Entry<String, String> entry : map.entrySet()) {                if ("appid".equals(entry.getKey())) {                  appId = entry.getValue();                } else if ("prepay_id".equals(entry.getKey())) {                  prepayId = entry.getValue();                } else if ("nonce_str".equals(entry.getKey())) {                  nonceStr = entry.getValue();                }              }              Log.d(TAG, "run: :" + appId + "/" + prepayId + "/" + nonceStr + "/");              String TimeStamp = String.valueOf(genTimeStamp());              //ok 获取二次签名              String secondPackageSign = genSecondPackageSign(getSecondSignParams(appId, prepayId, nonceStr, TimeStamp));              PayReq req = new PayReq();              req.appId = appId;              req.partnerId = "商户号";              req.prepayId = prepayId;              req.nonceStr = nonceStr;              req.timeStamp = TimeStamp;              req.packageValue = "Sign=WXPay";              req.sign = secondPackageSign;              req.extData = "app data"; // optional              //      System.out.println("genPackageSign3:"+post.getSign()+"/"+secondPackageSign);              // 在支付之前，如果应用没有注册到微信，应该先调用IWXMsg.registerApp将应用注册到微信              mApi.sendReq(req);              Log.d(TAG, "run: " + appId + "/" + prepayId + "/" + nonceStr + "/" + TimeStamp + "/" + secondPackageSign);            }          }        } catch (Exception e) {        }

public static byte[] httpPost(String url, String entity) {    if (url == null || url.length() == 0) {      Log.e(TAG, "httpPost, url is null");      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) {        Log.e(TAG, "httpGet fail, status code = " + resp.getStatusLine().getStatusCode());        return null;      }      return EntityUtils.toByteArray(resp.getEntity());    } catch (Exception e) {      Log.e(TAG, "httpPost exception, e = " + e.getMessage());      e.printStackTrace();      return null;    }  }

   //获取随机字符串的方法  public static String genNonceStr() {    Random random = new Random();    return MD5.getMessageDigest(String.valueOf(random.nextInt(10000)).getBytes());  }

 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>");    return sb.toString();  }

 public Map<String, String> decodeXml(String content) {    try {      Map<String, String> xml = new HashMap<>();      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)) {              xml.put(nodeName, parser.nextText());            }            break;          case XmlPullParser.END_TAG:            break;        }        event = parser.next();      }      return xml;    } catch (Exception e) {    }    return null;  }

 @NonNull  private List<NameValuePair> getFirstSignParams(WXPrePost params) {    List<NameValuePair> packageParams = new LinkedList<>();    packageParams.add(new BasicNameValuePair("appid", "appId"));    packageParams.add(new BasicNameValuePair("body", params.body));    packageParams.add(new BasicNameValuePair("detail", params.detail));    packageParams.add(new BasicNameValuePair("mch_id", "商户号"));    packageParams.add(new BasicNameValuePair("nonce_str", params.nonce_str));    packageParams.add(new BasicNameValuePair("notify_url", params.notify_url));    packageParams.add(new BasicNameValuePair("out_trade_no", params.out_trade_no));    packageParams.add(new BasicNameValuePair("spbill_create_ip", params.spbill_create_ip));    packageParams.add(new BasicNameValuePair("total_fee", params.total_fee + ""));    packageParams.add(new BasicNameValuePair("trade_type", params.trade_type));    packageParams.add(new BasicNameValuePair("sign", params.sign));    return packageParams;  }

public class WXPrePost {  //必须带的参数  public String appid;  //微信开放平台审核通过的应用APPID  public String mch_id;  //微信支付分配的商户号  public String nonce_str;  //随机字符串，不长于32位。推荐随机数生成算法  public String sign;  //签名，详见签名生成算法  public String body;  // 商品描述交易字段格式根据不同的应用场景按照以下格式：APP――需传入应用市场上的APP名字-实际商品名称，天天爱消除-游戏充值。  public String out_trade_no;  // 商户系统内部的订单号,32个字符内、可包含字母, 其他说明见商户订单号  public int total_fee;  // 订单总金额，单位为分，详见支付金额  public String spbill_create_ip;  // 用户端实际ip  public String notify_url;  // 接收微信支付异步通知回调地址，通知url必须为直接可访问的url，不能携带参数。(后台提供的)  public String trade_type;  // 支付类型  // 非必须携带的参数  public String device_info;  // 终端设备号(门店号或收银设备ID)，默认请传"WEB"  public String detail;  // 商品名称明细列表  public String attach;  // 附加数据，在查询API和支付通知中原样返回，该字段主要用于商户携带订单的自定义数据  public String fee_type;  // 符合ISO 4217标准的三位字母代码，默认人民币：CNY，其他值列表详见货币类型  //  public String time_start;  // 订单生成时间，格式为yyyyMMddHHmmss，如2009年12月25日9点10分10秒表示为20091225091010。其他详见时间规则  //  public String time_expire;  // 订单失效时间，格式为yyyyMMddHHmmss，如2009年12月27日9点10分10秒表示为20091227091010。其他详见时间规则 注意：最短失效时间间隔必须大于5分钟  public String goods_tag;  // 商品标记，代金券或立减优惠功能的参数，说明详见代金券或立减优惠  //  public String limit_pay;  //no_credit--指定不能使用信用卡支付  public String getAppid() {    return appid;  }  public void setAppid(String appid) {    this.appid = appid;  }  public String getMch_id() {    return mch_id;  }  public void setMch_id(String mch_id) {    this.mch_id = mch_id;  }  public String getNonce_str() {    return nonce_str;  }  public void setNonce_str(String nonce_str) {    this.nonce_str = nonce_str;  }  public String getSign() {    return sign;  }  public void setSign(String sign) {    this.sign = sign;  }  public String getBody() {    return body;  }  public void setBody(String body) {    this.body = body;  }  public String getOut_trade_no() {    return out_trade_no;  }  public void setOut_trade_no(String out_trade_no) {    this.out_trade_no = out_trade_no;  }  public int getTotal_fee() {    return total_fee;  }  public void setTotal_fee(int total_fee) {    this.total_fee = total_fee;  }  public String getSpbill_create_ip() {    return spbill_create_ip;  }  public void setSpbill_create_ip(String spbill_create_ip) {    this.spbill_create_ip = spbill_create_ip;  }  public String getNotify_url() {    return notify_url;  }  public void setNotify_url(String notify_url) {    this.notify_url = notify_url;  }  public String getTrade_type() {    return trade_type;  }  public void setTrade_type(String trade_type) {    this.trade_type = trade_type;  }  public String getDevice_info() {    return device_info;  }  public void setDevice_info(String device_info) {    this.device_info = device_info;  }  public String getDetail() {    return detail;  }  public void setDetail(String detail) {    this.detail = detail;  }  public String getAttach() {    return attach;  }  public void setAttach(String attach) {    this.attach = attach;  }  public String getFee_type() {    return fee_type;  }  public void setFee_type(String fee_type) {    this.fee_type = fee_type;  }  public String getTime_start() {    return time_start;  }  public void setTime_start(String time_start) {    this.time_start = time_start;  }  public String getTime_expire() {    return time_expire;  }  public void setTime_expire(String time_expire) {    this.time_expire = time_expire;  }  public String getGoods_tag() {    return goods_tag;  }  public void setGoods_tag(String goods_tag) {    this.goods_tag = goods_tag;  }  public String getLimit_pay() {    return limit_pay;  }  public void setLimit_pay(String limit_pay) {    this.limit_pay = limit_pay;  }}

if (resp.getType() == ConstantsAPI.COMMAND_PAY_BY_WX) {      int code = resp.errCode;      switch (code) {        case 0:          Log.d(TAG, "onPayFinish, errCode = " + "支付成功");          //微信支付成功后去调后台，以后台返回的支付结果为准          //这里是微信支付完成后的回调，在这里请求后台，让他来告诉我们到底支付成功没。          break;        case -1:          Toast.makeText(this, "支付失败1", Toast.LENGTH_SHORT).show();          Log.d(TAG, "onPayFinish, errCode = " + "支付失败1");          finish();          break;        case -2:          Toast.makeText(this, "支付取消", Toast.LENGTH_SHORT).show();          Log.d(TAG, "onPayFinish, errCode = " + "支付取消");          finish();          break;        default://          Toast.makeText(this, "支付失败2", Toast.LENGTH_SHORT).show();          Log.d(TAG, "onPayFinish, errCode = " + "支付失败2");          setResult(RESULT_OK);          finish();          break;      }    }