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 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 parameters){

StringBuffer sb = new StringBuffer();

sb.append("");

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+">");

}

else {

sb.append(""+v+""+k+">");

}

}

sb.append(""+""+"sign"+">");

sb.append("");

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("");

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 signParams = new TreeMap();

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

)

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 signParam = new TreeMap();

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("&timestamp=").append(seconds).append("&sign=").append(signAgain);//拼接参数返回给移动端

return weiXinVo.toString();