JAVA微信掃碼支付模式二線上支付功能實(shí)現(xiàn)以及回調(diào)

更新時(shí)間：2016年11月09日 17:03:20 作者：wangqiuyun

本篇文章主要介紹了JAVA微信掃碼支付模式二線上支付功能實(shí)現(xiàn)以及回調(diào)，這里整理了詳細(xì)的代碼,有需要的小伙伴可以參考下。

一、準(zhǔn)備工作

首先吐槽一下微信關(guān)于支付這塊，本身支持的支付模式就好幾種，但是官方文檔特別零散，連像樣的Java相關(guān)的demo也沒(méi)幾個(gè)。本人之前沒(méi)有搞過(guò)微信支付，一開始真是被它搞暈，折騰兩天終于調(diào)通了，特此寫下來(lái)，以享后人吧！

關(guān)于準(zhǔn)備工作，就“微信掃碼支付模式二”官方文檔地址在這 https://pay.weixin.qq.com/wiki/doc/api/native.php?chapter=6_1 可以先看看，實(shí)際上需要準(zhǔn)備的東西有以下幾個(gè)：

其中APP_ID和APP_SECRET可以在公眾平臺(tái)找著，MCH_ID和API_KEY則在商戶平臺(tái)找到，特別是API_KEY要在商戶平臺(tái)設(shè)置好，對(duì)于“微信掃碼支付模式二”（支付與回調(diào)）實(shí)際只會(huì)用到APP_ID、MCH_ID和API_KEY，其他的都不用。

關(guān)于開發(fā)環(huán)境，我就不羅嗦了，不管你是springMVC、struts2又或者直接serverlet，都差不多，只要你能保證對(duì)應(yīng)的方法能調(diào)用起來(lái)就行。關(guān)于引用第三方的jar包，我這里只用到了一個(gè)xml操作的jdom，記住是1.*的版本，不是官網(wǎng)上最新的2.*，兩者不兼容。具體是jdom-1.1.3.jar，依賴包jaxen-1.1.6.jar，就這兩個(gè)包，我沒(méi)用到有些例子中使用的httpclient，感覺沒(méi)必要，而且依賴包特別繁雜，當(dāng)然你是maven當(dāng)我沒(méi)說(shuō)。

二、開發(fā)實(shí)戰(zhàn)

1、首先是接入微信接口，獲取微信支付二維碼。

public String weixin_pay() throws Exception { 
    // 賬號(hào)信息 
    String appid = PayConfigUtil.APP_ID; // appid 
    //String appsecret = PayConfigUtil.APP_SECRET; // appsecret 
    String mch_id = PayConfigUtil.MCH_ID; // 商業(yè)號(hào) 
    String key = PayConfigUtil.API_KEY; // key 
 
    String currTime = PayCommonUtil.getCurrTime(); 
    String strTime = currTime.substring(8, currTime.length()); 
    String strRandom = PayCommonUtil.buildRandom(4) + ""; 
    String nonce_str = strTime + strRandom; 
     
    String order_price = 1; // 價(jià)格  注意：價(jià)格的單位是分 
    String body = "goodssssss";  // 商品名稱 
    String out_trade_no = "11338"; // 訂單號(hào) 
     
    // 獲取發(fā)起電腦 ip 
    String spbill_create_ip = PayConfigUtil.CREATE_IP; 
    // 回調(diào)接口  
    String notify_url = PayConfigUtil.NOTIFY_URL; 
    String trade_type = "NATIVE"; 
     
    SortedMap<Object,Object> packageParams = new TreeMap<Object,Object>(); 
    packageParams.put("appid", appid); 
    packageParams.put("mch_id", mch_id); 
    packageParams.put("nonce_str", nonce_str); 
    packageParams.put("body", body); 
    packageParams.put("out_trade_no", out_trade_no); 
    packageParams.put("total_fee", order_price); 
    packageParams.put("spbill_create_ip", spbill_create_ip); 
    packageParams.put("notify_url", notify_url); 
    packageParams.put("trade_type", trade_type); 
 
    String sign = PayCommonUtil.createSign("UTF-8", packageParams,key); 
    packageParams.put("sign", sign); 
     
    String requestXML = PayCommonUtil.getRequestXml(packageParams); 
    System.out.println(requestXML); 
  
    String resXml = HttpUtil.postData(PayConfigUtil.UFDODER_URL, requestXML); 
 
     
    Map map = XMLUtil.doXMLParse(resXml); 
    //String return_code = (String) map.get("return_code"); 
    //String prepay_id = (String) map.get("prepay_id"); 
    String urlCode = (String) map.get("code_url"); 
     
    return urlCode; 
}

如果不出意外的話，這里就從微信服務(wù)器獲取了一個(gè)支付url，形如weixin://wxpay/bizpayurl?pr=pIxXXXX，之后我們就需要把這個(gè)url生成一個(gè)二維碼，然后就可以使用自己手機(jī)微信端掃碼支付了。關(guān)于二維碼生成有很多種方法，各位各取所需吧，我這里提供一個(gè)google的二維碼生成接口：

public static String QRfromGoogle(String chl) throws Exception { 
  int widhtHeight = 300; 
  String EC_level = "L"; 
  int margin = 0; 
  chl = UrlEncode(chl); 
  String QRfromGoogle = "http://chart.apis.google.com/chart?chs=" + widhtHeight + "x" + widhtHeight 
      + "&cht=qr&chld=" + EC_level + "|" + margin + "&chl=" + chl; 
 
  return QRfromGoogle; 
}

// 特殊字符處理 
public static String UrlEncode(String src) throws UnsupportedEncodingException { 
  return URLEncoder.encode(src, "UTF-8").replace("+", "%20"); 
}

上面代碼中涉及到幾個(gè)工具類：PayConfigUtil、PayCommonUtil、HttpUtil和XMLUtil，其中PayConfigUtil放的就是上面提到一些配置及路徑，PayCommonUtil涉及到了獲取當(dāng)前事件、產(chǎn)生隨機(jī)字符串、獲取參數(shù)簽名和拼接xml幾個(gè)方法，代碼如下：

public class PayCommonUtil { 
   
  /** 
   * 是否簽名正確,規(guī)則是:按參數(shù)名稱a-z排序,遇到空值的參數(shù)不參加簽名。 
   * @return boolean 
   */ 
  public static boolean isTenpaySign(String characterEncoding, SortedMap<Object, Object> packageParams, String API_KEY) { 
    StringBuffer sb = new StringBuffer(); 
    Set es = packageParams.entrySet(); 
    Iterator it = es.iterator(); 
    while(it.hasNext()) { 
      Map.Entry entry = (Map.Entry)it.next(); 
      String k = (String)entry.getKey(); 
      String v = (String)entry.getValue(); 
      if(!"sign".equals(k) && null != v && !"".equals(v)) { 
        sb.append(k + "=" + v + "&"); 
      } 
    } 
     
    sb.append("key=" + API_KEY); 
     
    //算出摘要 
    String mysign = MD5Util.MD5Encode(sb.toString(), characterEncoding).toLowerCase(); 
    String tenpaySign = ((String)packageParams.get("sign")).toLowerCase(); 
     
    //System.out.println(tenpaySign + "  " + mysign); 
    return tenpaySign.equals(mysign); 
  } 
 
  /** 
   * @author 
   * @date 2016-4-22 
   * @Description：sign簽名 
   * @param characterEncoding 
   *      編碼格式 
   * @param parameters 
   *      請(qǐng)求參數(shù) 
   * @return 
   */ 
  public static String createSign(String characterEncoding, SortedMap<Object, Object> packageParams, String API_KEY) { 
    StringBuffer sb = new StringBuffer(); 
    Set es = packageParams.entrySet(); 
    Iterator it = es.iterator(); 
    while (it.hasNext()) { 
      Map.Entry entry = (Map.Entry) it.next(); 
      String k = (String) entry.getKey(); 
      String v = (String) entry.getValue(); 
      if (null != v && !"".equals(v) && !"sign".equals(k) && !"key".equals(k)) { 
        sb.append(k + "=" + v + "&"); 
      } 
    } 
    sb.append("key=" + API_KEY); 
    String sign = MD5Util.MD5Encode(sb.toString(), characterEncoding).toUpperCase(); 
    return sign; 
  } 
 
  /** 
   * @author 
   * @date 2016-4-22 
   * @Description：將請(qǐng)求參數(shù)轉(zhuǎn)換為xml格式的string 
   * @param parameters 
   *      請(qǐng)求參數(shù) 
   * @return 
   */ 
  public static String getRequestXml(SortedMap<Object, Object> parameters) { 
    StringBuffer sb = new StringBuffer(); 
    sb.append("<xml>"); 
    Set es = parameters.entrySet(); 
    Iterator it = es.iterator(); 
    while (it.hasNext()) { 
      Map.Entry entry = (Map.Entry) it.next(); 
      String k = (String) entry.getKey(); 
      String v = (String) entry.getValue(); 
      if ("attach".equalsIgnoreCase(k) || "body".equalsIgnoreCase(k) || "sign".equalsIgnoreCase(k)) { 
        sb.append("<" + k + ">" + "<![CDATA[" + v + "]]></" + k + ">"); 
      } else { 
        sb.append("<" + k + ">" + v + "</" + k + ">"); 
      } 
    } 
    sb.append("</xml>"); 
    return sb.toString(); 
  } 
 
  /** 
   * 取出一個(gè)指定長(zhǎng)度大小的隨機(jī)正整數(shù). 
   * 
   * @param length 
   *      int 設(shè)定所取出隨機(jī)數(shù)的長(zhǎng)度。length小于11 
   * @return int 返回生成的隨機(jī)數(shù)。 
   */ 
  public static int buildRandom(int length) { 
    int num = 1; 
    double random = Math.random(); 
    if (random < 0.1) { 
      random = random + 0.1; 
    } 
    for (int i = 0; i < length; i++) { 
      num = num * 10; 
    } 
    return (int) ((random * num)); 
  } 
 
  /** 
   * 獲取當(dāng)前時(shí)間 yyyyMMddHHmmss 
   * 
   * @return String 
   */ 
  public static String getCurrTime() { 
    Date now = new Date(); 
    SimpleDateFormat outFormat = new SimpleDateFormat("yyyyMMddHHmmss"); 
    String s = outFormat.format(now); 
    return s; 
  } 
 
}

HttpUtil和XMLUtil如下：

public class HttpUtil { 
 
  private static final Log logger = Logs.get(); 
  private final static int CONNECT_TIMEOUT = 5000; // in milliseconds 
  private final static String DEFAULT_ENCODING = "UTF-8"; 
   
  public static String postData(String urlStr, String data){ 
    return postData(urlStr, data, null); 
  } 
   
  public static String postData(String urlStr, String data, String contentType){ 
    BufferedReader reader = null; 
    try { 
      URL url = new URL(urlStr); 
      URLConnection conn = url.openConnection(); 
      conn.setDoOutput(true); 
      conn.setConnectTimeout(CONNECT_TIMEOUT); 
      conn.setReadTimeout(CONNECT_TIMEOUT); 
      if(contentType != null) 
        conn.setRequestProperty("content-type", contentType); 
      OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream(), DEFAULT_ENCODING); 
      if(data == null) 
        data = ""; 
      writer.write(data);  
      writer.flush(); 
      writer.close();  
 
      reader = new BufferedReader(new InputStreamReader(conn.getInputStream(), DEFAULT_ENCODING)); 
      StringBuilder sb = new StringBuilder(); 
      String line = null; 
      while ((line = reader.readLine()) != null) { 
        sb.append(line); 
        sb.append("\r\n"); 
      } 
      return sb.toString(); 
    } catch (IOException e) { 
      logger.error("Error connecting to " + urlStr + ": " + e.getMessage()); 
    } finally { 
      try { 
        if (reader != null) 
          reader.close(); 
      } catch (IOException e) { 
      } 
    } 
    return null; 
  } 
}

public class XMLUtil { 
  /** 
   * 解析xml,返回第一級(jí)元素鍵值對(duì)。如果第一級(jí)元素有子節(jié)點(diǎn)，則此節(jié)點(diǎn)的值是子節(jié)點(diǎn)的xml數(shù)據(jù)。 
   * @param strxml 
   * @return 
   * @throws JDOMException 
   * @throws IOException 
   */ 
  public static Map doXMLParse(String strxml) throws JDOMException, IOException { 
    strxml = strxml.replaceFirst("encoding=\".*\"", "encoding=\"UTF-8\""); 
 
    if(null == strxml || "".equals(strxml)) { 
      return null; 
    } 
     
    Map m = new HashMap(); 
     
    InputStream in = new ByteArrayInputStream(strxml.getBytes("UTF-8")); 
    SAXBuilder builder = new SAXBuilder(); 
    Document doc = builder.build(in); 
    Element root = doc.getRootElement(); 
    List list = root.getChildren(); 
    Iterator it = list.iterator(); 
    while(it.hasNext()) { 
      Element e = (Element) it.next(); 
      String k = e.getName(); 
      String v = ""; 
      List children = e.getChildren(); 
      if(children.isEmpty()) { 
        v = e.getTextNormalize(); 
      } else { 
        v = XMLUtil.getChildrenText(children); 
      } 
       
      m.put(k, v); 
    } 
     
    //關(guān)閉流 
    in.close(); 
     
    return m; 
  } 
   
  /** 
   * 獲取子結(jié)點(diǎn)的xml 
   * @param children 
   * @return String 
   */ 
  public static String getChildrenText(List children) { 
    StringBuffer sb = new StringBuffer(); 
    if(!children.isEmpty()) { 
      Iterator it = children.iterator(); 
      while(it.hasNext()) { 
        Element e = (Element) it.next(); 
        String name = e.getName(); 
        String value = e.getTextNormalize(); 
        List list = e.getChildren(); 
        sb.append("<" + name + ">"); 
        if(!list.isEmpty()) { 
          sb.append(XMLUtil.getChildrenText(list)); 
        } 
        sb.append(value); 
        sb.append("</" + name + ">"); 
      } 
    } 
     
    return sb.toString(); 
  } 
   
}

當(dāng)然還有一個(gè)MD5計(jì)算工具類

public class MD5Util { 
 
  private static String byteArrayToHexString(byte b[]) { 
    StringBuffer resultSb = new StringBuffer(); 
    for (int i = 0; i < b.length; i++) 
      resultSb.append(byteToHexString(b[i])); 
 
    return resultSb.toString(); 
  } 
 
  private static String byteToHexString(byte b) { 
    int n = b; 
    if (n < 0) 
      n += 256; 
    int d1 = n / 16; 
    int d2 = n % 16; 
    return hexDigits[d1] + hexDigits[d2]; 
  } 
 
  public static String MD5Encode(String origin, String charsetname) { 
    String resultString = null; 
    try { 
      resultString = new String(origin); 
      MessageDigest md = MessageDigest.getInstance("MD5"); 
      if (charsetname == null || "".equals(charsetname)) 
        resultString = byteArrayToHexString(md.digest(resultString 
            .getBytes())); 
      else 
        resultString = byteArrayToHexString(md.digest(resultString 
            .getBytes(charsetname))); 
    } catch (Exception exception) { 
    } 
    return resultString; 
  } 
 
  private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5", 
      "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" }; 
 
}

2、支付回調(diào)

支付完成后，微信會(huì)把相關(guān)支付結(jié)果和用戶信息發(fā)送到我們上面指定的那個(gè)回調(diào)地址，我們需要接收處理，并返回應(yīng)答。對(duì)后臺(tái)通知交互時(shí)，如果微信收到商戶的應(yīng)答不是成功或超時(shí)，微信認(rèn)為通知失敗，微信會(huì)通過(guò)一定的策略定期重新發(fā)起通知，盡可能提高通知的成功率，但微信不保證通知最終能成功。（通知頻率為15/15/30/180/1800/1800/1800/1800/3600，單位：秒）

關(guān)于支付回調(diào)接口，我們首先要對(duì)于支付結(jié)果通知的內(nèi)容進(jìn)行簽名驗(yàn)證，然后根據(jù)支付結(jié)果進(jìn)行相應(yīng)的處理流程即可。

public void weixin_notify(HttpServletRequest request,HttpServletResponse response) throws Exception{ 
     
    //讀取參數(shù) 
    InputStream inputStream ; 
    StringBuffer sb = new StringBuffer(); 
    inputStream = request.getInputStream(); 
    String s ; 
    BufferedReader in = new BufferedReader(new InputStreamReader(inputStream, "UTF-8")); 
    while ((s = in.readLine()) != null){ 
      sb.append(s); 
    } 
    in.close(); 
    inputStream.close(); 
 
    //解析xml成map 
    Map<String, String> m = new HashMap<String, String>(); 
    m = XMLUtil.doXMLParse(sb.toString()); 
     
    //過(guò)濾空 設(shè)置 TreeMap 
    SortedMap<Object,Object> packageParams = new TreeMap<Object,Object>();    
    Iterator it = m.keySet().iterator(); 
    while (it.hasNext()) { 
      String parameter = (String) it.next(); 
      String parameterValue = m.get(parameter); 
       
      String v = ""; 
      if(null != parameterValue) { 
        v = parameterValue.trim(); 
      } 
      packageParams.put(parameter, v); 
    } 
     
    // 賬號(hào)信息 
    String key = PayConfigUtil.API_KEY; // key 
 
    logger.info(packageParams); 
    //判斷簽名是否正確 
    if(PayCommonUtil.isTenpaySign("UTF-8", packageParams,key)) { 
      //------------------------------ 
      //處理業(yè)務(wù)開始 
      //------------------------------ 
      String resXml = ""; 
      if("SUCCESS".equals((String)packageParams.get("result_code"))){ 
        // 這里是支付成功 
        //////////執(zhí)行自己的業(yè)務(wù)邏輯//////////////// 
        String mch_id = (String)packageParams.get("mch_id"); 
        String openid = (String)packageParams.get("openid"); 
        String is_subscribe = (String)packageParams.get("is_subscribe"); 
        String out_trade_no = (String)packageParams.get("out_trade_no"); 
         
        String total_fee = (String)packageParams.get("total_fee"); 
         
        logger.info("mch_id:"+mch_id); 
        logger.info("openid:"+openid); 
        logger.info("is_subscribe:"+is_subscribe); 
        logger.info("out_trade_no:"+out_trade_no); 
        logger.info("total_fee:"+total_fee); 
         
        //////////執(zhí)行自己的業(yè)務(wù)邏輯//////////////// 
         
        logger.info("支付成功"); 
        //通知微信.異步確認(rèn)成功.必寫.不然會(huì)一直通知后臺(tái).八次之后就認(rèn)為交易失敗了. 
        resXml = "<xml>" + "<return_code><![CDATA[SUCCESS]]></return_code>" 
            + "<return_msg><![CDATA[OK]]></return_msg>" + "</xml> "; 
         
      } else { 
        logger.info("支付失敗,錯(cuò)誤信息：" + packageParams.get("err_code")); 
        resXml = "<xml>" + "<return_code><![CDATA[FAIL]]></return_code>" 
            + "<return_msg><![CDATA[報(bào)文為空]]></return_msg>" + "</xml> "; 
      } 
      //------------------------------ 
      //處理業(yè)務(wù)完畢 
      //------------------------------ 
      BufferedOutputStream out = new BufferedOutputStream( 
          response.getOutputStream()); 
      out.write(resXml.getBytes()); 
      out.flush(); 
      out.close(); 
    } else{ 
      logger.info("通知簽名驗(yàn)證失敗"); 
    } 
     
  }

簽名驗(yàn)證算法和簽名生成的算法類似，在上面PayCommonUtil工具類中提供。
三、后話

感覺微信掃描支付體驗(yàn)效果還是挺好的，唯一缺點(diǎn)就是相關(guān)文檔零散，官方的demo居然沒(méi)有java編寫的，希望之后微信官方能夠逐步完善吧！