public class PayCommonUtil {
//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 static 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=" + ConstantUtil.PARTNER_KEY);//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 static 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();
}
}
//微信Md5加密工具
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" };
}
//微信返回的结果为Xml格式的字符串，XmlUtil主要用于解析结果
public class XMLUtil {
/**
* 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 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);
}
//关闭流
in.close();
return m;
}
/**
* 获取子结点的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();
}
/**
* 获取xml编码字符集
* @param strxml
* @return
* @throws IOException
* @throws JDOMException
*/
public static String getXMLEncoding(String strxml) throws JDOMException, IOException {
InputStream in = HttpClientUtil.String2Inputstream(strxml);
SAXBuilder builder = new SAXBuilder();
Document doc = builder.build(in);
in.close();
return (String)doc.getProperty("encoding");
}
}
//发送https
public class CommonUtil {
private static Logger log = LoggerFactory.getLogger(CommonUtil.class);
/**
* 发送https请求
* @param requestUrl 请求地址
* @param requestMethod 请求方式（GET、POST）
* @param outputStr 提交的数据
* @return 返回微信服务器响应的信息
*/
public static String httpsRequest(String requestUrl, String requestMethod, String outputStr) {
try {
// 创建SSLContext对象，并使用我们指定的信任管理器初始化
MyX509TrustManager[] tm = { new MyX509TrustManager() };
SSLContext sslContext = SSLContext.getInstance("SSL", "SunJSSE");
sslContext.init(null, tm, new java.security.SecureRandom());
// 从上述SSLContext对象中得到SSLSocketFactory对象
SSLSocketFactory ssf = sslContext.getSocketFactory();
URL url = new URL(requestUrl);
HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
conn.setSSLSocketFactory(ssf);
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) {
log.error("连接超时：{}", ce);
} catch (Exception e) {
log.error("https请求异常：{}", e);
}
return null;
}
/**
* 获取接口访问凭证
*
* @param appid 凭证
* @param appsecret 密钥
* @return
*//*
public static Token getToken(String appid, String appsecret) {
Token token = null;
String requestUrl = ConfigUtil.TOKEN_URL.replace("APPID", appid).replace("APPSECRET", appsecret);
// 发起GET请求获取凭证
JSONObject jsonObject = JSONObject.fromObject(httpsRequest(requestUrl, "GET", null));
if (null != jsonObject) {
try {
token = new Token();
token.setAccessToken(jsonObject.getString("access_token"));
token.setExpiresIn(jsonObject.getInt("expires_in"));
} catch (JSONException e) {
token = null;
// 获取token失败
log.error("获取token失败 errcode:{} errmsg:{}", jsonObject.getInt("errcode"), jsonObject.getString("errmsg"));
}
}
return token;
}
public static String urlEncodeUTF8(String source){
String result = source;
try {
result = java.net.URLEncoder.encode(source,"utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return result;
}*/
}
重点：封装参数调用统一下单接口，生成prepay_id(预支付订单Id)
/**
* 微信支付
* @param orderId 订单编号
* @param actualPay 实际支付金额
* @return
*/
private String generateOrderInfoByWeiXinPay(String orderId, float actualPay,HttpServletRequest request,HttpServletResponse response) throws Exception{
String notify_url = propertiesService.WEI_XIN_NOTIFY_URL;//回调地址
String uuid = IdGen.uuid();
System.out.print("uuid" + uuid);
SortedMap<String, String> signParams = new TreeMap<String, String>();
signParams.put("appid", ConstantUtil.APP_ID);//app_id
signParams.put("body","测试");//商品参数信息
signParams.put("mch_id", ConstantUtil.PARTNER);//微信商户账号
signParams.put("nonce_str", uuid);//32位不重复的编号
signParams.put("notify_url", notify_url);//回调页面
signParams.put("out_trade_no", orderId);//订单编号
signParams.put("spbill_create_ip",request.getRemoteAddr() );//请求的实际ip地址
signParams.put("total_fee","1");//支付金额 单位为分
signParams.put("trade_type", "APP");付款类型为APP
String sign = PayCommonUtil.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 = PayCommonUtil.getRequestXml(signParams);//生成Xml格式的字符串
String result = CommonUtil.httpsRequest (ConstantUtil.UNIFIED_ORDER_URL, "POST", requestXml);//以post请求的方式调用统一下单接口
（注：ConstantUtil.UNIFIED_ORDER_URL=https://api.mch.weixin.qq.com/pay/unifiedorder;
）
返回的result成功结果取出prepay_id：
Map map = XMLUtil.doXMLParse(result);
String return_code=(String) map.get("return_code");
String prepay_id =null;
String returnSign=null;
String returnNonce_str=null;
if (return_code.contains("SUCCESS")){
prepay_id=(String) map.get("prepay_id");//获取到prepay_id
}
StringBuffer weiXinVo=new StringBuffer();
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", ConstantUtil.APP_ID);//app_id
signParam.put("partnerid", ConstantUtil.PARTNER);//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", uuid);//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 = PayCommonUtil.createSign("UTF-8", signParam);//再次生成签名
signParams.put("sign", signAgain);
weiXinVo.append("appid=").append(ConstantUtil.APP_ID).append("&partnerid=").append(ConstantUtil.PARTNER).append("&prepayid=").append(prepay_id).append("&package=Sign=WXPay").append("&noncestr=").append(uuid).append("×tamp=").append(seconds).append("&sign=").append(signAgain);//拼接参数返回给移动端
return weiXinVo.toString();
（注：感谢IOS团队的联调支持）
微信APP支付（Java后台生成签名具体步骤）