java微信app支付-统一下单

估计大多数人和我一样吧，每次要使用腾讯的开发api，都有一种想上吊的感觉，尤其是微信支付和支付宝对比起来文档确实差距还是有点大的

关于微信支付的申请我就不多说了，网上有很多，我们直接来说一下微信支付

微信支付是以下步骤（官方文档说明 https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=8_3）
步骤1：用户在商户APP中选择商品，提交订单，选择微信支付。

步骤2：商户后台收到用户支付单，调用微信支付统一下单接口。参见【统一下单API】。

步骤3：统一下单接口返回正常的prepay_id，再按签名规范重新生成签名后，将数据传输给APP。参与签名的字段名为appId，partnerId，prepayId，nonceStr，timeStamp，package。注意：package的值格式为Sign=WXPay

      步骤3要注意千万不要按照他给的签名字段进行前面，我就被坑了一天

     appid

     partnerid

     prepayid

     package

     noncestr

     timestamp

     sign

  
签名字段一定不要按照文档的驼峰写法，应该是全部小写，就像上面

步骤4：商户APP调起微信支付。api参见本章节【app端开发步骤说明】

步骤5：商户后台接收支付通知。api参见【支付结果通知API】

步骤6：商户后台查询支付结果。，api参见【查询订单API】

接下来我们就开始讲解统一下单

请求URL地址：https://api.mch.weixin.qq.com/pay/unifiedorder

参数

字段名	变量名	必填	类型	示例值	描述
应用ID	appid	是	String(32)	wxd678efh567hg6787	微信开放平台审核通过的应用APPID
商户号	mch_id	是	String(32)	1230000109	微信支付分配的商户号
设备号	device_info	否	String(32)	013467007045764	终端设备号(门店号或收银设备ID)，默认请传"WEB"
随机字符串	nonce_str	是	String(32)	5K8264ILTKCH16CQ2502SI8ZNMTM67VS	随机字符串，不长于32位。推荐随机数生成算法
签名	sign	是	String(32)	C380BEC2BFD727A4B6845133519F3AD6	签名，详见签名生成算法
商品描述	body	是	String(128)	Ipad mini  16G  白色	商品或支付单简要描述
商品详情	detail	否	String(8192)	Ipad mini  16G  白色	商品名称明细列表
附加数据	attach	否	String(127)	深圳分店	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
商户订单号	out_trade_no	是	String(32)	20150806125346	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
货币类型	fee_type	否	String(16)	CNY	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
总金额	total_fee	是	Int	888	订单总金额，单位为分，详见支付金额
终端IP	spbill_create_ip	是	String(16)	123.12.12.123	用户端实际ip
交易起始时间	time_start	否	String(14)	20091225091010	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
交易结束时间	time_expire	否	String(14)	20091227091010	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
商品标记	goods_tag	否	String(32)	WXG	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
通知地址	notify_url	是	String(256)	http://www.weixin.qq.com/wxpay/pay.php	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。
交易类型	trade_type	是	String(16)	APP	支付类型
指定支付方式	limit_pay	否	String(32)	no_credit	no_credit--指定不能使用信用卡支付

我们先上工具类吧

public class PayCommonUtil {
//微信参数配置
public static String API_KEY="";
public static String APPID="";
public static String MCH_ID="";
//随机字符串生成
public static String getRandomString(int length) { //length表示生成字符串的长度
String base = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
Random random = new Random();
StringBuffer sb = new StringBuffer();
for (int i = 0; i < length; i++) {
int number = random.nextInt(base.length());
sb.append(base.charAt(number));
}
return sb.toString();
}
//请求xml组装
public static String getRequestXml(SortedMap<String,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 key = (String)entry.getKey();
String value = (String)entry.getValue();
if ("attach".equalsIgnoreCase(key)||"body".equalsIgnoreCase(key)||"sign".equalsIgnoreCase(key)) {
sb.append("<"+key+">"+"<![CDATA["+value+"]]></"+key+">");
}else {
sb.append("<"+key+">"+value+"</"+key
4000
+">");
}
}
sb.append("</xml>");
return sb.toString();
}
//生成签名
public static String createSign(String characterEncoding,SortedMap<String,Object> 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=" + API_KEY);
String sign = MD5Util.MD5Encode(sb.toString(), characterEncoding).toUpperCase();
return sign;
}
//请求方法
public static String httpsRequest(String requestUrl, String requestMethod, String outputStr) {
try {

URL url = new URL(requestUrl);
HttpURLConnection conn = (HttpURLConnection) 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 (ConnectException ce) {
System.out.println("连接超时：{}"+ ce);
} catch (Exception e) {
System.out.println("https请求异常：{}"+ e);
}
return null;
}
//退款的请求方法
public static String httpsRequest2(String requestUrl, String requestMethod, String outputStr) throws Exception {
KeyStore keyStore  = KeyStore.getInstance("PKCS12");
StringBuilder res = new StringBuilder("");
FileInputStream instream = new FileInputStream(new File("/home/apiclient_cert.p12"));
try {
keyStore.load(instream, "".toCharArray());
} finally {
instream.close();
}

// Trust own CA and all self-signed certs
SSLContext sslcontext = SSLContexts.custom()
.loadKeyMaterial(keyStore, "1313329201".toCharArray())
.build();
// Allow TLSv1 protocol only
SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
sslcontext,
new String[] { "TLSv1" },
null,
SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);
CloseableHttpClient httpclient = HttpClients.custom()
.setSSLSocketFactory(sslsf)
.build();
try {

HttpPost httpost = new HttpPost("https://api.mch.weixin.qq.com/secapi/pay/refund");
httpost.addHeader("Connection", "keep-alive");
httpost.addHeader("Accept", "*/*");
httpost.addHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
httpost.addHeader("Host", "api.mch.weixin.qq.com");
httpost.addHeader("X-Requested-With", "XMLHttpRequest");
httpost.addHeader("Cache-Control", "max-age=0");
httpost.addHeader("User-Agent", "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0) ");
StringEntity entity2 = new StringEntity(outputStr ,Consts.UTF_8);
httpost.setEntity(entity2);
System.out.println("executing request" + httpost.getRequestLine());

CloseableHttpResponse response = httpclient.execute(httpost);

try {
HttpEntity entity = response.getEntity();

System.out.println("----------------------------------------");
System.out.println(response.getStatusLine());
if (entity != null) {
System.out.println("Response content length: " + entity.getContentLength());
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(entity.getContent()));
String text;res.append(text);
while ((text = bufferedReader.readLine()) != null) {
res.append(text);
System.out.println(text);
}

}
EntityUtils.consume(entity);
} finally {
response.close();
}
} finally {
httpclient.close();
}
return  res.toString();

}
//xml解析
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 = getChildrenText(children);
}

m.put(k, v);
}

//关闭流
in.close();

return m;
}

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(getChildrenText(list));
}
sb.append(value);
sb.append("</" + name + ">");
}
}

return sb.toString();
}

}

统一下单

参数说明

sn订单号

totalAmount支付金额

description产品描述

public static Map<String, String> weixinPrePay(String sn,BigDecimal totalAmount,
String description, HttpServletRequest request) {
Setting setting = SettingUtils.get();
SortedMap<String, Object> parameterMap = new TreeMap<String, Object>();
parameterMap.put("appid", PayCommonUtil.APPID);
parameterMap.put("mch_id", PayCommonUtil.MCH_ID);
parameterMap.put("nonce_str", PayCommonUtil.getRandomString(32));
parameterMap.put("body",
StringUtils.abbreviate(description.replaceAll(
"[^0-9a-zA-Z\\u4e00-\\u9fa5 ]", ""), 600));
parameterMap.put("out_trade_no", sn);
parameterMap.put("fee_type", "CNY");
System.out.println("jiner");
BigDecimal total = totalAmount.multiply(new BigDecimal(100));
java.text.DecimalFormat df=new java.text.DecimalFormat("0");
parameterMap.put("total_fee", df.format(total));
System.out.println("jiner2");
parameterMap.put("spbill_create_ip", request.getRemoteAddr());
parameterMap.put("notify_url", "http://xxx.com");
parameterMap.put("trade_type", "APP");
System.out.println("");
String sign = PayCommonUtil.createSign("UTF-8", parameterMap);
System.out.println("jiner2");
parameterMap.put("sign", sign);
String requestXML = PayCommonUtil.getRequestXml(parameterMap);
System.out.println(requestXML);
String result = PayCommonUtil.httpsRequest(
"https://api.mch.weixin.qq.com/pay/unifiedorder", "POST",
requestXML);
System.out.println(result);
Map<String, String> map = null;
try {
map = PayCommonUtil.doXMLParse(result);
} catch (JDOMException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return map;
}

获取prepay_id，二次签名发送结果给app，此方法结合业务自己优化一下，这里只是举个例子

public static String createSignAgain(HttpServletRequest request)
Map<String, String> map = weixinPrePay(payment.getSn(), payment.getAmount(),description,
request);
JSONObject jsonObject = new JSONObject();
SortedMap<String, Object> parameterMap = new TreeMap<String, Object>();
parameterMap.put("appid", PayCommonUtil.APPID);
parameterMap.put("partnerid", PayCommonUtil.MCH_ID);
parameterMap.put("prepayid", map.get("prepay_id"));
parameterMap.put("package", "Sign=WXPay");
parameterMap.put("noncestr", PayCommonUtil.getRandomString(32));
parameterMap.put("timestamp", System.currentTimeMillis());
String sign = PayCommonUtil.createSign("UTF-8", parameterMap);
parameterMap.put("sign", sign);
jsonObject.put("parameterMap",parameterMap);
return jsonObject.toString();
}

到此统一下下单完成，关于app支付我就不说了，下一篇说一下支付结果通用通知