微信小程序 支付后台java实现实例
前言：
前些天使用 LeanCloud 云引擎写了个小程序的支付相关 以前只做过 APP 支付 这次在小程序支付爬了两天的坑 把代码也分享出来
支付流程:
1.小程序前端获取微信 openId 以及订单号 传给后台
2,后台根据 openId 和订单号进行签名 post 微信统一下单接口
3.后台获取微信返回的xml字符串 解析 二次签名以后返回给前端
4.前端调起支付微信支付 API
先看支付函数:
//获取支付信息
@EngineFunction("getPayInformation")
public static Map<String, Object> getPayInformation(
@EngineFunctionParam("orderId") String orderId
) throws AVException, UnsupportedEncodingException, DocumentException {
Map<String, Object> reqMap = new TreeMap<String, Object>(
new Comparator<String>() {
public int compare(String obj1, String obj2) {
// 升序排序
return obj1.compareTo(obj2);
}
});
if (AVUser.getCurrentUser() != null) {
String authDataJson = JSONArray.toJSONString(AVUser.getCurrentUser().get("authData"));
JSONObject jsonObject = JSON.parseObject(authDataJson);
jsonObject.get("lc_weapp");
JSONObject j2 = JSON.parseObject(jsonObject.get("lc_weapp").toString());
String openId = (String) j2.get("openid");
AVQuery<Order> query = AVObject.getQuery(Order.class);
Order order = query.get(orderId);
reqMap.put("appid", System.getenv("appid"));
reqMap.put("mch_id", System.getenv("mch_id"));
reqMap.put("nonce_str", WXPayUtil.getNonce_str());
reqMap.put("body", new String(order.getDishesList().toString().getBytes("UTF-8")));
reqMap.put("openid", openId);
reqMap.put("out_trade_no", order.getObjectId());
reqMap.put("total_fee", 1); //订单总金额，单位为分
reqMap.put("spbill_create_ip", "192.168.0.1"); //用户端ip
reqMap.put("notify_url", System.getenv("notify_url")); //通知地址
reqMap.put("trade_type", System.getenv("trade_type")); //trade_type=JSAPI时（即公众号支付），此参数必传，此参数为微信用户在商户对应appid下的唯一标识
String reqStr = WXPayUtil.map2Xml(reqMap);
String resultXml = HttpRequest.sendPost(reqStr);
System.out.println("微信请求返回:" + resultXml);
//解析微信返回串 如果状态成功 则返回给前端
if (WXPayUtil.getReturnCode(resultXml) != null && WXPayUtil.getReturnCode(resultXml).equals("SUCCESS")) {
//成功
Map<String, Object> resultMap = new TreeMap<>(
new Comparator<String>() {
public int compare(String obj1, String obj2) {
// 升序排序
return obj1.compareTo(obj2);
}
});
resultMap.put("appId", System.getenv("appid"));
resultMap.put("nonceStr", WXPayUtil.getNonceStr(resultXml));//解析随机字符串
resultMap.put("package", "prepay_id=" + WXPayUtil.getPrepayId(resultXml));
resultMap.put("signType", "MD5");
resultMap.put("timeStamp", String.valueOf((System.currentTimeMillis() / 1000)));//时间戳
String paySign = WXPayUtil.getSign(resultMap);
resultMap.put("paySign", paySign);
return resultMap;
} else {
throw new AVException(999, "微信请求支付失败");
}
} else {
throw new AVException(98, "当前未登录用户");
}
}
其中appid和mch_id可以用系统常量
PS:这里注意一个坑
二次签名的时候使用 appId nonceStr package signType timeStamp 这五个key生成签名(这里无视微信官方文档 以及注意 appId 的大小写)
前端调起API支付时 按照官方文档就可以
网络请求类:
HttpRequest
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;
public class HttpRequest {
/**
* 向指定URL发送GET方法的请求
*
* @param url 发送请求的URL
* @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
* @return URL 所代表远程资源的响应结果
*/
public static String sendGet(String url, String param) {
String result = "";
BufferedReader in = null;
try {
String urlNameString = url + "?" + param;
URL realUrl = new URL(urlNameString);
// 打开和URL之间的连接
URLConnection connection = realUrl.openConnection();
// 设置通用的请求属性
connection.setRequestProperty("accept", "*/*");
connection.setRequestProperty("connection", "Keep-Alive");
connection.setRequestProperty("user-agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
// 建立实际的连接
connection.connect();
// 获取所有响应头字段
Map<String, List<String>> map = connection.getHeaderFields();
// 遍历所有的响应头字段
for (String key : map.keySet()) {
System.out.println(key + "--->" + map.get(key));
}
// 定义 BufferedReader输入流来读取URL的响应
in = new BufferedReader(new InputStreamReader(
connection.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
result += line;
}
} catch (Exception e) {
System.out.println("发送GET请求出现异常！" + e);
e.printStackTrace();
}
// 使用finally块来关闭输入流
finally {
try {
if (in != null) {
in.close();
}
} catch (Exception e2) {
e2.printStackTrace();
}
}
return result;
}
/**
* 向指定 URL 发送POST方法的请求
*
* @param url 发送请求的 URL
* @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
* @return 所代表远程资源的响应结果
*/
public static String sendPost(String param) {
PrintWriter out = null;
BufferedReader in = null;
String result = "";
try {
URL realUrl = new URL("https://api.mch.weixin.qq.com/pay/unifiedorder");
// 打开和URL之间的连接
URLConnection conn = realUrl.openConnection();
// 设置通用的请求属性
conn.setRequestProperty("accept", "*/*");
conn.setRequestProperty("connection", "Keep-Alive");
conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
// conn.setRequestProperty("Pragma:", "no-cache");
// conn.setRequestProperty("Cache-Control", "no-cache");
// conn.setRequestProperty("Content-Type", "text/xml;charset=utf-8");
// 发送POST请求必须设置如下两行
conn.setDoOutput(true);
conn.setDoInput(true);
// 获取URLConnection对象对应的输出流
out = new PrintWriter(conn.getOutputStream());
// 发送请求参数
out.print(param);
// flush输出流的缓冲
out.flush();
// 定义BufferedReader输入流来读取URL的响应
in = new BufferedReader(
new InputStreamReader(conn.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
result += line;
}
} catch (Exception e) {
System.out.println("发送 POST 请求出现异常！" + e);
e.printStackTrace();
}
//使用finally块来关闭输出流、输入流
finally {
try {
if (out != null) {
out.close();
}
if (in != null) {
in.close();
}
} catch (IOException ex) {
ex.printStackTrace();
}
}
return result;
}
}
XML解析工具类
WXPayUtil
import org.w3c.dom.NodeList;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.Map;
import java.util.Random;
public class WXPayUtil {
//生成随机字符串
public static String getNonce_str() {
String base = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
Random random = new Random();
StringBuilder sb = new StringBuilder();
for (int i = 0; i < 15; i++) {
int number = random.nextInt(base.length());
sb.append(base.charAt(number));
}
return sb.toString();
}
//map转xml 加上签名信息
public static String map2Xml(Map<String, Object> map) throws UnsupportedEncodingException {
StringBuffer sb = new StringBuffer();
StringBuilder sb2 = new StringBuilder();
sb2.append("<xml>");
for (String key : map.keySet()) {
sb.append(key);
sb.append('=');
sb.append(map.get(key));
sb.append('&');
// sb2是用来做请求的xml参数
sb2.append("<" + key + ">");
// sb2.append("<![CDATA[" + map.get(key) + "]]>");
sb2.append(map.get(key));
sb2.append("</" + key + ">");
}
sb.append(System.getenv("signKey"));
String sign = MD5.getMessageDigest(sb.toString().getBytes()).toUpperCase();
sb2.append("<sign>");
sb2.append(sign);
sb2.append("</sign>");
sb2.append("</xml>");
return sb2.toString();
}
//解析微信返回return_code SUCCESS或FILE
//根据微信返回resultXml再次生成签名
public static String getSign(Map<String, Object> map) {
StringBuffer sb = new StringBuffer();
for (String key : map.keySet()) {
sb.append(key);
sb.append('=');
sb.append(map.get(key));
sb.append('&');
}
sb.append(System.getenv("signKey"));
System.out.println("第二次签名内容:" + sb);
System.out.println("第二次签名SING:" + MD5.getMessageDigest(sb.toString().getBytes()).toUpperCase());
return MD5.getMessageDigest(sb.toString().getBytes()).toUpperCase();
}
//解析微信返回return_code SUCCESS或FILE
public static String getReturnCode(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("return_code");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
//解析微信返回return_msg
public static String getReturn_msg(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("return_msg");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
//解析微信返回appid
public static String getAppId(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("appid");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
//解析微信返回mch_id
public static String getMchId(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("mch_id");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
//解析微信返回nonce_str
public static String getNonceStr(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("nonce_str");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
//解析微信返回prepay_id
public static String getPrepayId(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("prepay_id");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}
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