微信小程序支付（java后端）

第一步 

进入小程序，下单，请求下单支付，调用小程序登录API来获取Openid（https://mp.weixin.qq.com/debug/w ... .html#wxloginobject）,生成商户订单，这些都是在小程序端完成的业务。 

小程序端代码 

1. // pages/pay/pay.js
2. var app = getApp();
3. Page({
4. data: {},
5. onLoad: function (options) {
6. // 页面初始化 options为页面跳转所带来的参数
7. },
8. /* 微信支付 */
9. wxpay: function () {
10. var that = this
11. //登陆获取code
12. wx.login({
13. success: function (res) {
14. console.log(res.code)
15. //获取openid
16. that.getOpenId(res.code)
17. }
18. });
19. },
20. getOpenId: function (code) {
21. var that = this;
22. wx.request({
23. url: "https://api.weixin.qq.com/sns/jscode2session?appid=wxa142513e524e496c&secret=5d6a7d86048884e7c60f84f7aa85253c&js_code=" + code + "&grant_type=authorization_code",
24. data: {},
25. method: 'GET',
26. success: function (res) {
27. console.log('返回openId')
28. console.log(res.data)
29. that.generateOrder(res.data.openid)
30. },
31. fail: function () {
32. // fail
33. },
34. complete: function () {
35. // complete
36. }
37. })
38. },
39. /**生成商户订单 */
40. generateOrder: function (openid) {
41. var that = this
42. //统一支付
43. wx.request({
44. url: 'http://localhost:8070/RMS/pay_pay.action',
45. method: 'GET',
46. data: {
47. total_fee: '5',
48. body: '支付测试',
49. attach:'真假酒水'
50. },
51. success: function (res) {
52. console.log(res)
53. var pay = res.data
54. //发起支付
55. var timeStamp = pay[0].timeStamp;
56. console.log("timeStamp:"+timeStamp)
57. var packages = pay[0].package;
58. console.log("package:"+packages)
59. var paySign = pay[0].paySign;
60. console.log("paySign:"+paySign)
61. var nonceStr = pay[0].nonceStr;
62. console.log("nonceStr:"+nonceStr)
63. var param = { "timeStamp": timeStamp, "package": packages, "paySign": paySign, "signType": "MD5", "nonceStr": nonceStr };
64. that.pay(param)
65. },
66. })
67. },
68. /* 支付 */
69. pay: function (param) {
70. console.log("支付")
71. console.log(param)
72. wx.requestPayment({
73. timeStamp: param.timeStamp,
74. nonceStr: param.nonceStr,
75. package: param.package,
76. signType: param.signType,
77. paySign: param.paySign,
78. success: function (res) {
79. // success
80. console.log("支付")
81. console.log(res)
82. wx.navigateBack({
83. delta: 1, // 回退前 delta(默认为1) 页面
84. success: function (res) {
85. wx.showToast({
86. title: '支付成功',
87. icon: 'success',
88. duration: 2000
89. })
90. },
91. fail: function () {
92. // fail
93. },
94. complete: function () {
95. // complete
96. }
97. })
98. },
99. fail: function (res) {
100. // fail
101. console.log("支付失败")
102. console.log(res)
103. },
104. complete: function () {
105. // complete
106. console.log("pay complete")
107. }
108. })
109. }
110. })

第二步 
调用支付统一下单API来获取prepay_id，并将小程序调起支付数据需要签名的字段appId，timeStamp，nonceStr，package再次签名（https://pay.weixin.qq.com/wiki/d ... ter=7_7&index=3） 

后台代码 

1. package cn.it.shop.action;
2. import java.io.ByteArrayInputStream;
3. import java.io.InputStream;
4. import java.io.UnsupportedEncodingException;
5. import java.text.SimpleDateFormat;
6. import java.util.Date;
7. import java.util.HashMap;
8. import java.util.List;
9. import java.util.Map;
10. import org.dom4j.Document;
11. import org.dom4j.DocumentException;
12. import org.dom4j.Element;
13. import org.dom4j.io.SAXReader;
14. import cn.it.shop.util.MessageUtil;
15. import cn.it.shop.util.PayUtil;
16. import cn.it.shop.util.PaymentPo;
17. import cn.it.shop.util.UUIDHexGenerator;
18. import net.sf.json.JSONArray;
19. import net.sf.json.JSONObject;
20. /**
21. * @author
22. * @version 创建时间：2017年1月21日 下午4:59:03
23. * 小程序端请求的后台action，返回签名后的数据传到前台
24. */
25. public class PayAction {
26. private String total_fee;//总金额
27. private String body;//商品描述
28. private String detail;//商品详情
29. private String attach;//附加数据
30. private String time_start;//交易起始时间
31. private String time_expire;//交易结束时间
32. private String openid;//用户标识
33. private JSONArray jsonArray=new JSONArray();
34. public String pay() throws UnsupportedEncodingException, DocumentException{
35. body = new String(body.getBytes("UTF-8"),"ISO-8859-1");
36. String appid = "替换为自己的小程序ID";//小程序ID
37. String mch_id = "替换为自己的商户号";//商户号
38. String nonce_str = UUIDHexGenerator.generate();//随机字符串
39. String today = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date());
40. String code = PayUtil.createCode(8);
41. String out_trade_no = mch_id+today+code;//商户订单号
42. String spbill_create_ip = "替换为自己的终端IP";//终端IP
43. String notify_url = "http://www.weixin.qq.com/wxpay/pay.php";//通知地址
44. String trade_type = "JSAPI";//交易类型
45. String openid="替换为用户的openid";//用户标识
46. /**/
47. PaymentPo paymentPo = new PaymentPo();
48. paymentPo.setAppid(appid);
49. paymentPo.setMch_id(mch_id);
50. paymentPo.setNonce_str(nonce_str);
51. String newbody=new String(body.getBytes("ISO-8859-1"),"UTF-8");//以utf-8编码放入paymentPo，微信支付要求字符编码统一采用UTF-8字符编码
52. paymentPo.setBody(newbody);
53. paymentPo.setOut_trade_no(out_trade_no);
54. paymentPo.setTotal_fee(total_fee);
55. paymentPo.setSpbill_create_ip(spbill_create_ip);
56. paymentPo.setNotify_url(notify_url);
57. paymentPo.setTrade_type(trade_type);
58. paymentPo.setOpenid(openid);
59. // 把请求参数打包成数组
60. Map sParaTemp = new HashMap();
61. sParaTemp.put("appid", paymentPo.getAppid());
62. sParaTemp.put("mch_id", paymentPo.getMch_id());
63. sParaTemp.put("nonce_str", paymentPo.getNonce_str());
64. sParaTemp.put("body", paymentPo.getBody());
65. sParaTemp.put("out_trade_no", paymentPo.getOut_trade_no());
66. sParaTemp.put("total_fee",paymentPo.getTotal_fee());
67. sParaTemp.put("spbill_create_ip", paymentPo.getSpbill_create_ip());
68. sParaTemp.put("notify_url",paymentPo.getNotify_url());
69. sParaTemp.put("trade_type", paymentPo.getTrade_type());
70. sParaTemp.put("openid", paymentPo.getOpenid());
71. // 除去数组中的空值和签名参数
72. Map sPara = PayUtil.paraFilter(sParaTemp);
73. String prestr = PayUtil.createLinkString(sPara); // 把数组所有元素，按照“参数=参数值”的模式用“&”字符拼接成字符串
74. String key = "&key=替换为商户支付**"; // 商户支付**
75. //MD5运算生成签名
76. String mysign = PayUtil.sign(prestr, key, "utf-8").toUpperCase();
77. paymentPo.setSign(mysign);
78. //打包要发送的xml
79. String respXml = MessageUtil.messageToXML(paymentPo);
80. // 打印respXml发现，得到的xml中有“__”不对，应该替换成“_”
81. respXml = respXml.replace("__", "_");
82. String url = "https://api.mch.weixin.qq.com/pay/unifiedorder";//统一下单API接口链接
83. String param = respXml;
84. //String result = SendRequestForUrl.sendRequest(url, param);//发起请求
85. String result =PayUtil.httpRequest(url, "POST", param);
86. // 将解析结果存储在HashMap中
87. Map map = new HashMap();
88. InputStream in=new ByteArrayInputStream(result.getBytes());
89. // 读取输入流
90. SAXReader reader = new SAXReader();
91. Document document = reader.read(in);
92. // 得到xml根元素
93. Element root = document.getRootElement();
94. // 得到根元素的所有子节点
95. @SuppressWarnings("unchecked")
96. List elementList = root.elements();
97. for (Element element : elementList) {
98. map.put(element.getName(), element.getText());
99. }
100. // 返回信息
101. String return_code = map.get("return_code");//返回状态码
102. String return_msg = map.get("return_msg");//返回信息
103. System.out.println("return_msg"+return_msg);
104. JSONObject JsonObject=new JSONObject() ;
105. if(return_code=="SUCCESS"||return_code.equals(return_code)){
106. // 业务结果
107. String prepay_id = map.get("prepay_id");//返回的预付单信息
108. String nonceStr=UUIDHexGenerator.generate();
109. JsonObject.put("nonceStr", nonceStr);
110. JsonObject.put("package", "prepay_id="+prepay_id);
111. Long timeStamp= System.currentTimeMillis()/1000;
112. JsonObject.put("timeStamp", timeStamp+"");
113. String stringSignTemp = "appId="+appid+"&nonceStr=" + nonceStr + "&package=prepay_id=" + prepay_id+ "&signType=MD5&timeStamp=" + timeStamp;
114. //再次签名
115. String paySign=PayUtil.sign(stringSignTemp, "&key=替换为自己的**", "utf-8").toUpperCase();
116. JsonObject.put("paySign", paySign);
117. jsonArray.add(JsonObject);
118. }
119. return "pay";
120. }
121. public String getTotal_fee() {
122. return total_fee;
123. }
124. public void setTotal_fee(String total_fee) {
125. this.total_fee = total_fee;
126. }
127. public String getBody() {
128. return body;
129. }
130. public void setBody(String body) {
131. this.body = body;
132. }
133. public JSONArray getJsonArray() {
134. return jsonArray;
135. }
136. public void setJsonArray(JSONArray jsonArray) {
137. this.jsonArray = jsonArray;
138. }
139. public String getDetail() {
140. return detail;
141. }
142. public void setDetail(String detail) {
143. this.detail = detail;
144. }
145. public String getAttach() {
146. return attach;
147. }
148. public void setAttach(String attach) {
149. this.attach = attach;
150. }
151. public String getTime_start() {
152. return time_start;
153. }
154. public void setTime_start(String time_start) {
155. this.time_start = time_start;
156. }
157. public String getTime_expire() {
158. return time_expire;
159. }
160. public void setTime_expire(String time_expire) {
161. this.time_expire = time_expire;
162. }
163. public String getOpenid() {
164. return openid;
165. }
166. public void setOpenid(String openid) {
167. this.openid = openid;
168. }
169. }

后台业务逻辑涉及到的工具类及参数封装类 
MessageUtil 

1. package cn.it.shop.util;
2. import java.io.IOException;
3. import java.io.Writer;
4. import java.util.HashMap;
5. import java.util.List;
6. import javax.servlet.http.HttpServletRequest;
7. import org.dom4j.Document;
8. import org.dom4j.Element;
9. import org.dom4j.io.SAXReader;
10. import com.thoughtworks.xstream.XStream;
11. import com.thoughtworks.xstream.core.util.QuickWriter;
12. import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
13. import com.thoughtworks.xstream.io.xml.PrettyPrintWriter;
14. import com.thoughtworks.xstream.io.xml.XppDriver;
15. public class MessageUtil {
16. public static HashMap parseXML(HttpServletRequest request) throws Exception, IOException{
17. HashMap map=new HashMap();
18. // 通过IO获得Document
19. SAXReader reader = new SAXReader();
20. Document doc = reader.read(request.getInputStream());
21. //得到xml的根节点
22. Element root=doc.getRootElement();
23. recursiveParseXML(root,map);
24. return map;
25. }
26. private static void recursiveParseXML(Element root,HashMap map){
27. //得到根节点的子节点列表
28. List elementList=root.elements();
29. //判断有没有子元素列表
30. if(elementList.size()==0){
31. map.put(root.getName(), root.getTextTrim());
32. }
33. else{
34. //遍历
35. for(Element e:elementList){
36. recursiveParseXML(e,map);
37. }
38. }
39. }
40. private static XStream xstream = new XStream(new XppDriver() {
41. public HierarchicalStreamWriter createWriter(Writer out) {
42. return new PrettyPrintWriter(out) {
43. // 对所有xml节点都增加CDATA标记
44. boolean cdata = true;
45. public void startNode(String name, Class clazz) {
46. super.startNode(name, clazz);
47. }
48. protected void writeText(QuickWriter writer, String text) {
49. if (cdata) {
50. writer.write(" writer.write(text);
51. writer.write("]]>");
52. } else {
53. writer.write(text);
54. }
55. }
56. };
57. }
58. });
59. public static String messageToXML(PaymentPo paymentPo){
60. xstream.alias("xml",PaymentPo.class);
61. return xstream.toXML(paymentPo);
62. }
63. }

PaymentPo//封装支付参数实体 

1. package cn.it.shop.util;
2. /**
3. * @author
4. * @version 创建时间：2017年1月21日 下午4:20:52
5. * 类说明
6. */
7. public class PaymentPo {
8. private String appid;//小程序ID
9. private String mch_id;//商户号
10. private String device_info;//设备号
11. private String nonce_str;//随机字符串
12. private String sign;//签名
13. private String body;//商品描述
14. private String detail;//商品详情
15. private String attach;//附加数据
16. private String out_trade_no;//商户订单号
17. private String fee_type;//货币类型
18. private String spbill_create_ip;//终端IP
19. private String time_start;//交易起始时间
20. private String time_expire;//交易结束时间
21. private String goods_tag;//商品标记
22. private String total_fee;//总金额
23. private String notify_url;//通知地址
24. private String trade_type;//交易类型
25. private String limit_pay;//指定支付方式
26. private String openid;//用户标识
27. set/get//省略
28. }

PayUtil

1. package cn.it.shop.util;
2. import java.io.BufferedReader;
3. import java.io.InputStream;
4. import java.io.InputStreamReader;
5. import java.io.OutputStream;
6. import java.io.UnsupportedEncodingException;
7. import java.net.HttpURLConnection;
8. import java.net.URL;
9. import java.util.ArrayList;
10. import java.util.Collections;
11. import java.util.HashMap;
12. import java.util.List;
13. import java.util.Map;
14. import org.apache.commons.codec.digest.DigestUtils;
15. /**
16. * @author
17. * @version 创建时间：2017年1月17日 下午7:46:29 类说明
18. */
19. public class PayUtil {
20. /**
21. * 签名字符串
22. * @param text需要签名的字符串
23. * @param key **
24. * @param input_charset编码格式
25. * @return 签名结果
26. */
27. public static String sign(String text, String key, String input_charset) {
28. text = text + key;
29. return DigestUtils.md5Hex(getContentBytes(text, input_charset));
30. }
31. /**
32. * 签名字符串
33. * @param text需要签名的字符串
34. * @param sign 签名结果
35. * @param key**
36. * @param input_charset 编码格式
37. * @return 签名结果
38. */
39. public static boolean verify(String text, String sign, String key, String input_charset) {
40. text = text + key;
41. String mysign = DigestUtils.md5Hex(getContentBytes(text, input_charset));
42. if (mysign.equals(sign)) {
43. return true;
44. } else {
45. return false;
46. }
47. }
48. /**
49. * @param content
50. * @param charset
51. * @return
52. * @throws SignatureException
53. * @throws UnsupportedEncodingException
54. */
55. public static byte[] getContentBytes(String content, String charset) {
56. if (charset == null || "".equals(charset)) {
57. return content.getBytes();
58. }
59. try {
60. return content.getBytes(charset);
61. } catch (UnsupportedEncodingException e) {
62. throw new RuntimeException("MD5签名过程中出现错误,指定的编码集不对,您目前指定的编码集是:" + charset);
63. }
64. }
65. /**
66. * 生成6位或10位随机数 param codeLength(多少位)
67. * @return
68. */
69. public static String createCode(int codeLength) {
70. String code = "";
71. for (int i = 0; i < codeLength; i++) {
72. code += (int) (Math.random() * 9);
73. }
74. return code;
75. }
76. private static boolean isValidChar(char ch) {
77. if ((ch >= '0' && ch <= '9') || (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z'))
78. return true;
79. if ((ch >= 0x4e00 && ch <= 0x7fff) || (ch >= 0x8000 && ch <= 0x952f))
80. return true;// 简体中文汉字编码
81. return false;
82. }
83. /**
84. * 除去数组中的空值和签名参数
85. * @param sArray 签名参数组
86. * @return 去掉空值与签名参数后的新签名参数组
87. */
88. public static Map paraFilter(Map sArray) {
89. Map result = new HashMap();
90. if (sArray == null || sArray.size() <= 0) {
91. return result;
92. }
93. for (String key : sArray.keySet()) {
94. String value = sArray.get(key);
95. if (value == null || value.equals("") || key.equalsIgnoreCase("sign")
96. || key.equalsIgnoreCase("sign_type")) {
97. continue;
98. }
99. result.put(key, value);
100. }
101. return result;
102. }
103. /**
104. * 把数组所有元素排序，并按照“参数=参数值”的模式用“&”字符拼接成字符串
105. * @param params 需要排序并参与字符拼接的参数组
106. * @return 拼接后字符串
107. */
108. public static String createLinkString(Map params) {
109. List keys = new ArrayList(params.keySet());
110. Collections.sort(keys);
111. String prestr = "";
112. for (int i = 0; i < keys.size(); i++) {
113. String key = keys.get(i);
114. String value = params.get(key);
115. if (i == keys.size() - 1) {// 拼接时，不包括最后一个&字符
116. prestr = prestr + key + "=" + value;
117. } else {
118. prestr = prestr + key + "=" + value + "&";
119. }
120. }
121. return prestr;
122. }
123. /**
124. *
125. * @param requestUrl请求地址
126. * @param requestMethod请求方法
127. * @param outputStr参数
128. */
129. public static String httpRequest(String requestUrl,String requestMethod,String outputStr){
130. // 创建SSLContext
131. StringBuffer buffer=null;
132. try{
133. URL url = new URL(requestUrl);
134. HttpURLConnection conn = (HttpURLConnection) url.openConnection();
135. conn.setRequestMethod(requestMethod);
136. conn.setDoOutput(true);
137. conn.setDoInput(true);
138. conn.connect();
139. //往服务器端写内容
140. if(null !=outputStr){
141. OutputStream os=conn.getOutputStream();
142. os.write(outputStr.getBytes("utf-8"));
143. os.close();
144. }
145. // 读取服务器端返回的内容
146. InputStream is = conn.getInputStream();
147. InputStreamReader isr = new InputStreamReader(is, "utf-8");
148. BufferedReader br = new BufferedReader(isr);
149. buffer = new StringBuffer();
150. String line = null;
151. while ((line = br.readLine()) != null) {
152. buffer.append(line);
153. }
154. }catch(Exception e){
155. e.printStackTrace();
156. }
157. return buffer.toString();
158. }
159. public static String urlEncodeUTF8(String source){
160. String result=source;
161. try {
162. result=java.net.URLEncoder.encode(source, "UTF-8");
163. } catch (UnsupportedEncodingException e) {
164. // TODO Auto-generated catch block
165. e.printStackTrace();
166. }
167. return result;
168. }
169. }

UUIDHexGenerator 

1. package cn.it.shop.util;
2. import java.net.InetAddress;
3. /**
4. * @author
5. * @version 创建时间：2017年1月17日 下午7:45:06 类说明
6. */
7. public class UUIDHexGenerator {
8. private static String sep = "";
9. private static final int IP;
10. private static short counter = (short) 0;
11. private static final int JVM = (int) (System.currentTimeMillis() >>>;
12. private static UUIDHexGenerator uuidgen = new UUIDHexGenerator();
13. static {
14. int ipadd;
15. try {
16. ipadd = toInt(InetAddress.getLocalHost().getAddress());
17. } catch (Exception e) {
18. ipadd = 0;
19. }
20. IP = ipadd;
21. }
22. public static UUIDHexGenerator getInstance() {
23. return uuidgen;
24. }
25. public static int toInt(byte[] bytes) {
26. int result = 0;
27. for (int i = 0; i < 4; i++) {
28. result = (result << - Byte.MIN_VALUE + (int) bytes;
29. }
30. return result;
31. }
32. protected static String format(int intval) {
33. String formatted = Integer.toHexString(intval);
34. StringBuffer buf = new StringBuffer("00000000");
35. buf.replace(8 - formatted.length(), 8, formatted);
36. return buf.toString();
37. }
38. protected static String format(short shortval) {
39. String formatted = Integer.toHexString(shortval);
40. StringBuffer buf = new StringBuffer("0000");
41. buf.replace(4 - formatted.length(), 4, formatted);
42. return buf.toString();
43. }
44. protected static int getJVM() {
45. return JVM;
46. }
47. protected synchronized static short getCount() {
48. if (counter < 0) {
49. counter = 0;
50. }
51. return counter++;
52. }
53. protected static int getIP() {
54. return IP;
55. }
56. protected static short getHiTime() {
57. return (short) (System.currentTimeMillis() >>> 32);
58. }
59. protected static int getLoTime() {
60. return (int) System.currentTimeMillis();
61. }
62. public static String generate() {
63. return new StringBuffer(36).append(format(getIP())).append(sep).append(format(getJVM())).append(sep)
64. .append(format(getHiTime())).append(sep).append(format(getLoTime())).append(sep)
65. .append(format(getCount())).toString();
66. }
67. /**
68. * @param args
69. */
70. public static void main(String[] args) {
71. String id="";
72. UUIDHexGenerator uuid = UUIDHexGenerator.getInstance();
73. /*
74. for (int i = 0; i < 100; i++) {
75. id = uuid.generate();
76. }*/
77. id = uuid.generate();
78. System.out.println(id);
79. }
80. }

付源码：

链接：https://pan.baidu.com/s/1dFRVmiX 密码：dkx7