需要準備openid，appid，還有申請微信支付後要設定一個32位的密鑰，需要先生成一個sign，得到prepay_id，然後再得到一個paySign。
生成sign以及得到sign後生成XML工具類PayCommonUtil：
public class PayCommonUtil {
public static boolean isTenpaySign(String characterEncoding, SortedMap<String, String> 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);
}
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 = entry.getKey().toString();
String v = entry.getValue().toString();
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;
}
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 = entry.getKey().toString();
String v = entry.getValue().toString();
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();
}
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));
}
public static String getCurrTime() {
Date now = new Date();
SimpleDateFormat outFormat = new SimpleDateFormat("yyyyMMddHHmmss");
String s = outFormat.format(now);
return s;
}
public static String getRandomStringByLength(int length) {
String base = "abcdefghijklmnopqrstuvwxyz0123456789";
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();
}
通路官方接口得到含有prepay_id的XML工具類HttpUtil的公共類：
public class HttpUtil {
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) {
} finally {
try {
if (reader != null)
reader.close();
} catch (IOException e) {
}
}
return null;
}
}
解析XML工具類：
public class XMLUtil {
public static SortedMap<String, String> doXMLParse(String strxml) throws JDOMException, IOException {
strxml = strxml.replaceFirst("encoding=\".*\"", "encoding=\"UTF-8\"");
if(null == strxml || "".equals(strxml)) {
return null;
}
SortedMap<String, String> m = new TreeMap<>();
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);
}
//關閉流
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(XMLUtil.getChildrenText(list));
}
sb.append(value);
sb.append("</" + name + ">");
}
}
return sb.toString();
}
}
MD5加密工具類：
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" };
}
controller裡面的寫法：
@RequestMapping("/wechat/wxPay")
@EnableCORS
public class WxPayController extends WxBaseController {
@JbootrpcService
FinOrderService orderService;
@JbootrpcService
private FinOrderVideoService orderVideoService;
public void payOrder() {
// 得到openId
String openId = getWxOpenId();
if (!StrKit.isBlank(openId)) {
try {
String nonceStr = PayCommonUtil.getRandomStringByLength(32);
// 訂單id
String did = getPara("oid");
int price = 0;
// 得到小程式傳過來的價格，注意這裡的價格必須為整數，1代表1分，是以傳過來的值必須*100；
if (null != getParaToInt("price")) {
price = getParaToInt("price");
}
FinOrder order = orderService.findById(did);
SortedMap<Object, Object> packageParams = new TreeMap<>();
packageParams.put("appid", WxConsts.WECHAT_APPID);// 服務商ID
packageParams.put("mch_id", WxConsts.WECHAT_MCHID);// 商戶号
packageParams.put("nonce_str", nonceStr);// 随機字元串
packageParams.put("body", order.getBuName());// 商品描述
packageParams.put("out_trade_no", order.getOrdId());// 商戶訂單号
packageParams.put("total_fee", price);// 總金額
packageParams.put("notify_url", WxConsts.NOTIFY_URL);// 通知位址
packageParams.put("trade_type", WxConsts.TRADETYPE);// 交易類型 小程式取值：JSAPI
packageParams.put("openid", openId);// 使用者辨別
// 擷取sign
String sign = PayCommonUtil.createSign("UTF-8", packageParams, WxConsts.WECHAT_SECRET);// 最後這個是自己設定的32位密鑰
packageParams.put("sign", sign);
// 轉成XML
String requestXML = PayCommonUtil.getRequestXml(packageParams);
// 得到含有prepay_id的XML
String resXml = HttpUtil.postData("https://api.mch.weixin.qq.com/pay/unifiedorder", requestXML);
// 解析XML存入Map
Map map = XMLUtil.doXMLParse(resXml);
// 得到prepay_id
String prepayId = (String) map.get("prepay_id");
SortedMap<Object, Object> packageP = new TreeMap<>();
packageP.put("appId", WxConsts.WECHAT_APPID);// ！！！注意，這裡是appId,上面是appid，真懷疑寫這個東西的人。。。
packageP.put("nonceStr", nonceStr);// 時間戳
packageP.put("package", "prepay_id=" + prepayId);// 必須把package寫成 "prepay_id="+prepay_id這種形式
packageP.put("signType", WxConsts.SIGNTYPE);// paySign加密
packageP.put("timeStamp", (System.currentTimeMillis() / 1000) + "");
// 得到paySign
String paySign = PayCommonUtil.createSign("UTF-8", packageP, WxConsts.WECHAT_SECRET);
packageP.put("paySign", paySign);
// 将packageP資料傳回給小程式
renderJson(RestResult.buildSuccess(packageP));
} catch (Exception e) {
renderJson(RestResult.buildError());
}
} else {
renderJson(RestResult.buildError("使用者資訊擷取失敗"));
}
}
public void payNotify() {
try {
int ordId = getParaToInt("id");
String xmlString = "";
String lastXml = "";
xmlString = getPara();
// 先解析傳回的資料
SortedMap<String, String> dataMap = XMLUtil.doXMLParse(xmlString);
String returnCode = dataMap.get("return_code");
// 通信成功
if ("SUCCESS".equals(returnCode)) {
// 驗證通過才能記到流水表中，否則不計入
if (PayCommonUtil.isTenpaySign("UTF-8", dataMap, WxConsts.WECHAT_SECRET)) {
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
renderJson(RestResult.buildError("id不能為空"));
}
}
public void paySuccess() {
Long ordId = getParaToLong("id");
if (ordId != null) {
FinOrder model = new FinOrder();
model.setId(ordId);
model.setStatus(OrderStatus.PAID);
model.setStartTime(new Date());
boolean ret = orderService.update(model);
renderJson(RestResult.buildSuccess(ret));
} else {
renderJson(RestResult.buildError("id不能為空"));
}
}
}