java开发微信APP支付

直接上代码

String nonce_str=WXPayUtil.generateNonceStr();   //WXPayUtil微信自己有的,自己下载,这里是生成随机字符串,下载地址(下载java的里面就有):https://pay.weixin.qq.com/wiki/doc/api/native_sl.php?chapter=11_1

SortedMap<String, String> signParams = new TreeMap<String, String>();
signParams.put("appid", weChatConfig.getAppWxAppId());//app_id---需要申请
signParams.put("body",weChatConfig.getBody());//商品参数信息
signParams.put("mch_id", weChatConfig.getWxMchId());//微信商户账号--需要申请
signParams.put("nonce_str", nonce_str);//32位不重复的编号
signParams.put("notify_url", weChatConfig.getNotifyUrl());//回调页面--这个是回调接口
signParams.put("out_trade_no", orderUserId);//订单编号
BigDecimal transValue = new BigDecimal("100");
// 计算微信的总金额乘以100
BigDecimal bTotalPrice = totalPrice.multiply(transValue);
int totalFee = bTotalPrice.intValue();
signParams.put("total_fee",String.valueOf(totalFee));//支付金额 单位为分
signParams.put("trade_type", "APP"); //app支付
String sign = createSign("UTF-8", signParams);//生成签名
signParams.put("sign", sign);
signParams.remove("key");//调用统一下单无需key（商户应用密钥）
String requestXml = getRequestXml(signParams);//生成Xml格式的字符串
String result = CommonUtil.httpsRequest(weChatConfig.getWxPayUnifiedorderUrl(), "POST", requestXml);
//返回的result成功结果取出prepay_id：
Map map = null;
try {
   map = doXMLParse(result);
} catch (JDOMException e) {
   e.printStackTrace();
} catch (IOException e) {
   e.printStackTrace();
}
String return_code=(String) map.get("return_code");
String prepay_id =null;
if (return_code.contains("SUCCESS")){
   prepay_id=(String) map.get("prepay_id");//获取到prepay_id
}
long currentTimeMillis = System.currentTimeMillis();//生成时间戳
long second = currentTimeMillis / 1000L;//（转换成秒）
String seconds = String.valueOf(second).substring(0, 10);//（截取前10位）
SortedMap<String, String> signParam = new TreeMap<String, String>();
signParam.put("appid", weChatConfig.getAppWxAppId());//app_id
signParam.put("partnerid", weChatConfig.getWxMchId());//微信商户账号
signParam.put("prepayid", prepay_id);//预付订单id
signParam.put("package", "Sign=WXPay");//默认sign=WXPay
signParam.put("noncestr", nonce_str);//自定义不重复的长度不长于32位
signParam.put("timestamp",seconds);//北京时间时间戳
String signAgain = createSign("UTF-8", signParam);//再次生成签名
signParam.put("sign", signAgain);
return ApiResult.result(signParam);

其他

//定义签名，微信根据参数字段的ASCII码值进行排序 加密签名,故使用SortMap进行参数排序
public String createSign(String characterEncoding, SortedMap<String,String> parameters){
   StringBuffer sb = new StringBuffer();
   Set es = parameters.entrySet();
   Iterator it = es.iterator();
   while(it.hasNext()) {
      Map.Entry entry = (Map.Entry)it.next();
      String k = (String)entry.getKey();
      Object v = entry.getValue();
      if(null != v && !"".equals(v)
            && !"sign".equals(k) && !"key".equals(k)) {
         sb.append(k + "=" + v + "&");
      }
   }
   sb.append("key=" + weChatConfig.getWxApiKey());//最后加密时添加商户密钥，由于key值放在最后，所以不用添加到SortMap里面去，单独处理，编码方式采用UTF-8
   String sign = MD5Util.MD5Encode(sb.toString(), characterEncoding).toUpperCase();
   return sign;
}

//将封装好的参数转换成Xml格式类型的字符串

public String getRequestXml(SortedMap<String,String> 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("sign".equalsIgnoreCase(k)){

      }
      else if ("attach".equalsIgnoreCase(k)||"body".equalsIgnoreCase(k)) {
         sb.append("<"+k+">"+"<![CDATA["+v+"]]></"+k+">");
      }
      else {
         sb.append("<"+k+">"+v+"</"+k+">");
      }
   }
   sb.append("<"+"sign"+">"+"<![CDATA["+parameters.get("sign")+"]]></"+"sign"+">");
   sb.append("</xml>");
   return sb.toString();
}

/**
 * 解析xml,返回第一级元素键值对。如果第一级元素有子节点，则此节点的值是子节点的xml数据。
 * @param strxml
 * @return
 * @throws JDOMException
 * @throws IOException
 */
public 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 = getChildrenText(children);
      }

      m.put(k, v);
   }

   //关闭流
   in.close();

   return m;
}
/**
 * 获取子结点的xml
 * @param children
 * @return String
 */
public 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(getChildrenText(list));
         }
         sb.append(value);
         sb.append("</" + name + ">");
      }
   }

   return sb.toString();
}

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" };
}

public class CommonUtil {
   public static String httpsRequest(String requestUrl, String requestMethod, String outputStr) {
      try {
         URL url = new URL(requestUrl);
         HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
         conn.setDoOutput(true);
         conn.setDoInput(true);
         conn.setUseCaches(false);
         // 设置请求方式（GET/POST）
         conn.setRequestMethod(requestMethod);
         conn.setRequestProperty("content-type", "application/x-www-form-urlencoded");
         // 当outputStr不为null时向输出流写数据
         if (null != outputStr) {
            OutputStream outputStream = conn.getOutputStream();
            // 注意编码格式
            outputStream.write(outputStr.getBytes("UTF-8"));
            outputStream.close();
         }
         // 从输入流读取返回内容
         InputStream inputStream = conn.getInputStream();
         InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");
         BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
         String str = null;
         StringBuffer buffer = new StringBuffer();
         while ((str = bufferedReader.readLine()) != null) {
            buffer.append(str);
         }
         // 释放资源
         bufferedReader.close();
         inputStreamReader.close();
         inputStream.close();
         inputStream = null;
         conn.disconnect();
         return buffer.toString();
      } catch (Exception e) {
         e.printStackTrace();
      }
      return null;
   }

   public String httpRequest(String urlStr, String xml) throws UnsupportedEncodingException {
      StringBuilder sb = new StringBuilder();
      try {
         URL url = new URL(urlStr);
         URLConnection con = url.openConnection();
         con.setDoOutput(true);
         con.setRequestProperty("Pragma", "no-cache");// 【Pragma:】centos7报错,不合法
         con.setRequestProperty("Cache-Control", "no-cache");
         con.setRequestProperty("Content-Type", "text/xml");
         OutputStreamWriter out = new OutputStreamWriter(con.getOutputStream());
         out.write(new String(xml.getBytes("UTF-8")));
         out.flush();
         out.close();
         BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));
         String line = "";
         for (line = br.readLine(); line != null; line = br.readLine()) {
            sb.append(line);
         }
      } catch (MalformedURLException e) {
         e.printStackTrace();
      } catch (IOException e) {
         e.printStackTrace();
      }
      return new String(sb.toString().getBytes(), "UTF-8");
   }

}