java实现微信小程序退款
请仔细阅读微信退款文档 微信退款文档
申请退款
退款需要有证书，参照：安全规范第三条 API证书
/**
* @DESCRIPTION: 调用微信退款
*/
public void payOrderRefund() {
try {
//查询需要退款的金额
double refundMoney = 0.0;
if (验证退款金额,不验证也可以) {
//封装参数
Map<String, String> data = this.createData(refundMoney);
//MD5运算生成签名，这里是第一次签名，用于调用统一下单接口
//WeChat.KEY：微信支付的商户密钥，需要在微信后台设置，包括后面用到的 KEY 都是这个值
String mySign = this.sign(this.createLinkString(data), WeChat.KEY, "utf-8").toUpperCase();
data.put("sign", mySign);
log.info("退款 签名：" + mySign);
log.info("向微信服务器发送退款请求...");
//支付结果通知的xml格式数据
//退款的post请求方法需要有证书验证
String xmlStr = httpUtils.postData(""https://api.mch.weixin.qq.com/secapi/pay/refund"", this.GetMapToXML(data));
log.info("请求数据：" + xmlStr);
Map notifyMap = this.doXMLParse(xmlStr);
if (WeChat.SUCCESS.equals(notifyMap.get("return_code"))) {
if (WeChat.SUCCESS.equals(notifyMap.get("result_code"))) {
log.info("退款请求成功");
} else {
log.info("退款失败！原因：" + notifyMap.get("err_code_des"));
}
} else {
log.info("退款失败！原因：" + notifyMap.get("return_msg"));
}
}
} catch (Exception e) {
log.info("退款异常：" + e.getMessage());
e.printStackTrace();
}
}下面的工具方法可以和上面的放在一起也可以单独写一个工具类
封装退款参数
//封装退款请求需要的数据
private Map<String, String> createData(OrderItemDto orderItemDto, double refundMoney) {
Map<String, String> data = new HashMap<>();
//随机字符串
String nonce_str = PayUtil.getRandomStringByLength(32);
//商户订单号
String out_trade_no = orderItemDto.getOrderNo();
//商户退款订单号
String out_refund_no = PayUtil.createOrderNoOrRefundNo(orderItemDto.getHotelId());
//订单总金额 微信支付提交的金额是不能带小数点的，且是以分为单位,这边需要转成字符串类型，否则后面的签名会失败
String total_fee = String.valueOf((int) (orderItemDto.getAmount() * 100));
//退款总金额
String refund_fee = String.valueOf((int) (refundMoney * 100));
data.put("appid", appid);
data.put("mch_id", WeChat.MCH_ID);
data.put("nonce_str", nonce_str);
data.put("sign_type", WeChat.SIGNTYPE);
data.put("out_trade_no", out_trade_no);
data.put("out_refund_no", out_refund_no);
data.put("total_fee", total_fee);
data.put("refund_fee", refund_fee);
data.put("notify_url", WeChat.REFUND_NOTIFY_URL);
data.put("refund_desc", WeChat.REFUND_DESC);
return data;
}签名
/**
* 签名字符串
*
* @param text 需要签名的字符串
* @param key 商户平台设置的密钥
* @param input_charset 编码格式
* @return 签名结果
*/
public static String sign(String text, String key, String input_charset) {
text = text + "&key=" + key;
return DigestUtils.md5Hex(getContentBytes(text, input_charset));
}转换xml
public static String GetMapToXML(Map<String, String> param) {
StringBuffer sb = new StringBuffer();
sb.append("<xml>");
for (Map.Entry<String, String> entry : param.entrySet()) {
sb.append("<" + entry.getKey() + ">");
sb.append(entry.getValue());
sb.append("</" + entry.getKey() + ">");
}
sb.append("</xml>");
return sb.toString();
}解析xml
/**
* 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 IOException
*/
public static Map doXMLParse(String strxml) throws Exception {
if (stringUtils.isEmpty(strxml)) {
return null;
}
Map m = new HashMap();
InputStream in = String2Inputstream(strxml);
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 = getChildrenText(children);
}
m.put(k, v);
}
//关闭流
in.close();
return m;
}排序并按规则拼接
/**
* 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
*
* @param params 需要排序并参与字符拼接的参数组
* @return 拼接后字符串
*/
public static String createLinkString(Map<String, String> params) {
List<String> keys = new ArrayList<>(params.keySet());
Collections.sort(keys);
String prestr = "";
for (int i = 0; i < keys.size(); i++) {
String key = keys.get(i);
String value = params.get(key);
if (i == keys.size() - 1) {
// 拼接时，不包括最后一个&字符
prestr = prestr + key + "=" + value;
} else {
prestr = prestr + key + "=" + value + "&";
}
}
return prestr;
}http工具类
import lombok.extern.slf4j.Slf4j;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.ssl.SSLContexts;
import org.apache.http.util.EntityUtils;
import javax.net.ssl.SSLContext;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.KeyStore;
@Slf4j
public class httpUtils {
// 连接超时时间，默认10秒
private static int socketTimeout = 10000;
// 传输超时时间，默认30秒
private static int connectTimeout = 30000;
// HTTP请求器
private static CloseableHttpClient httpClient;
// 请求器的配置
private static RequestConfig requestConfig;
/**
* 加载证书
*/
private static void initCert() throws Exception {
// 证书密码，默认为商户ID
String key = "";
// 商户证书的路径
//public static final String CERT_PATH = "E:/workspace/apiclient_cert.p12"; //本地路径
String CERT_PATH = "/usr/local/dev/guns/cert/"; // 服务器路径
String path = CERT_PATH + "qcdr_cert.p12";
InputStream instream = null;
try {
// 读取本机存放的PKCS12证书文件
instream = new FileInputStream(new File(path));
/*ClassPathResource classPathResource = new ClassPathResource(path);
//获取文件流
instream = classPathResource.getInputStream();
instream = Thread.currentThread().getContextClassLoader().getResourceAsStream(path);*/
} catch (Exception e) {
log.error("商户证书不正确-->>" + e);
}
try {
// 指定读取证书格式为PKCS12
KeyStore keyStore = KeyStore.getInstance("PKCS12");
// 指定PKCS12的密码(商户ID)
keyStore.load(instream, key.toCharArray());
SSLContext sslcontext = SSLContexts.custom().loadKeyMaterial(keyStore, key.toCharArray()).build();
// 指定TLS版本
SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslcontext, new String[]{"TLSv1"}, null, SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);
// 设置httpclient的SSLSocketFactory
httpClient = HttpClients.custom().setSSLSocketFactory(sslsf).build();
} catch (Exception e) {
log.error("商户秘钥不正确-->>" + e);
} finally {
instream.close();
}
}
/**
* 通过Https往API post xml数据
*
* @param url 退款地址
* @param xmlObj 要提交的XML数据对象
* @return
*/
public static String postData(String url, String xmlObj) {
// 加载证书
try {
initCert();
} catch (Exception e) {
e.printStackTrace();
}
String result = null;
HttpPost httpPost = new HttpPost(url);
// 得指明使用UTF-8编码，否则到API服务器XML的中文不能被成功识别
StringEntity postEntity = new StringEntity(xmlObj, "UTF-8");
httpPost.addHeader("Content-Type", "text/xml");
httpPost.setEntity(postEntity);
// 根据默认超时限制初始化requestConfig
requestConfig = RequestConfig.custom()
.setSocketTimeout(socketTimeout)
.setConnectTimeout(connectTimeout)
.build();
// 设置请求器的配置
httpPost.setConfig(requestConfig);
try {
HttpResponse response = null;
try {
response = httpClient.execute(httpPost);
} catch (IOException e) {
e.printStackTrace();
}
HttpEntity entity = response.getEntity();
try {
result = EntityUtils.toString(entity, "UTF-8");
} catch (IOException e) {
e.printStackTrace();
}
} finally {
httpPost.abort();
}
return result;
}
/**
* @param requestUrl 请求地址
* @param requestMethod 请求方法
* @param outputStr 参数
*/
public static String httpRequest(String requestUrl, String requestMethod, String outputStr) {
// 创建SSLContext
StringBuffer buffer = null;
try {
URL url = new URL(requestUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod(requestMethod);
conn.setDoOutput(true);
conn.setDoInput(true);
conn.connect();
//往服务器端写内容
if (null != outputStr) {
OutputStream os = conn.getOutputStream();
os.write(outputStr.getBytes("utf-8"));
os.close();
}
// 读取服务器端返回的内容
InputStream is = conn.getInputStream();
InputStreamReader isr = new InputStreamReader(is, "utf-8");
BufferedReader br = new BufferedReader(isr);
buffer = new StringBuffer();
String line = null;
while ((line = br.readLine()) != null) {
buffer.append(line);
}
br.close();
} catch (Exception e) {
e.printStackTrace();
}
return buffer.toString();
}
}下面是小程序退款回调函数
退款回调函数
/**
* 微信退款回调函数
*/
public void payOrderRefundCallback(HttpServletRequest request, HttpServletResponse response) {
log.info("======================= 微信退款回调开始 =======================");
String inputLine = "";
String notityXml = "";
StringBuffer buffer = new StringBuffer();
buffer.append("<xml>");
try {
while ((inputLine = request.getReader().readLine()) != null) {
notityXml += inputLine;
}
//关闭流
request.getReader().close();
log.info("退款 微信回调内容信息：" + notityXml);
//解析成Map
Map map = this.doXMLParse(notityXml);
//判断 退款是否成功
if ("SUCCESS".equals(map.get("return_code").toString())) {
log.info("开始解密回调信息...");
//解密返回的加密信息
String passMap = AESUtil.decryptData(map.get("req_info").toString());
log.info("解密成功!");
//拿到解密信息
map = this.doXMLParse(passMap);
if ("SUCCESS".equals(map.get("refund_status"))) {
//退款回调成功，添加业务逻辑，可以修改订退款成功
buffer.append("<return_code><![CDATA[SUCCESS]]></return_code><return_msg><![CDATA[OK]]></return_msg>");
} else {
log.info("REFUNDCLOSE".equals(map.get("refund_status")) == true ? "退款关闭" : "退款异常");
buffer.append("<return_code><![CDATA[FAIL]]></return_code>");
buffer.append("<return_msg><![CDATA[退款异常]]></return_msg>");
}
} else {
log.info("退款 微信回调返回失败");
buffer.append("<return_code><![CDATA[FAIL]]></return_code>");
buffer.append("<return_msg><![CDATA[请求退款回调函数失败]]></return_msg>");
}
buffer.append("</xml>");
//给微信服务器返回 成功标识 否则会一直询问是否回调成功
PrintWriter writer = response.getWriter();
writer.print(buffer.toString());
log.info("退款回调通知微信的xml【" + buffer.toString() + "】");
} catch (Exception e) {
log.info("退款异常：" + e.getMessage());
System.out.println(e);
e.printStackTrace();
}
log.info("======================= 微信退款回调结束 =======================");
}解密回调字符串
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
public class AESUtil {
/**
* 密钥算法
*/
private static final String ALGORITHM = "AES";
/**
* 加解密算法/工作模式/填充方式
*/
private static final String ALGORITHM_MODE_PADDING = "AES/ECB/PKCS5Padding";
/**
* 生成key
*/
private static SecretKeySpec key = new SecretKeySpec(PayUtil.MD5Encode(WeChat.KEY, "UTF-8").toLowerCase().getBytes(), ALGORITHM);
/**
* AES加密
*
* @param data
* @return
* @throws Exception
*/
public static String encryptData(String data) throws Exception {
// 创建密码器
Cipher cipher = Cipher.getInstance(ALGORITHM_MODE_PADDING);
// 初始化
cipher.init(Cipher.ENCRYPT_MODE, key);
return PayUtil.encode(cipher.doFinal(data.getBytes()));
}
/**
* AES解密
*
* @param base64Data
* @return
* @throws Exception
*/
public static String decryptData(String base64Data) throws Exception {
Cipher cipher = Cipher.getInstance(ALGORITHM_MODE_PADDING);
cipher.init(Cipher.DECRYPT_MODE, key);
return new String(cipher.doFinal(PayUtil.decode(base64Data)));
}
}如果微信支付（退款）业务出现AES解密失败（Illegal key size or default parameters）
请参照：AES解密失败
至此整个微信小程序支付退款完成，如果有什么问题欢迎指出
微信小程序 支付 详细代码地址：微信小程序支付
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