Java实现微信的申请退款功能

Myth丶恋晨 2022-04-01 03:56 1034阅读 0赞

> 一，问题

今天要将微信的最后一个功能给做完了，这个功能就是申请退款。刚开始我先看了一下文档，发现它跟那个企业付款到零钱特别相似，然后就自己模仿企业付款到零钱把它给实现了。

> 二，解决方法

申请退款官方文档：`https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_4`

2.1 下载商家证书，再将证书放到项目中

①下载商家证书

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②将证书放到项目中

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Rhb3RpYW8wMTk5_size_16_color_FFFFFF_t_70 2]

2.2 将官方的demo下载下来，将里面的工具类全都放到项目中

官方demo下载地址：`https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=11_1`

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Rhb3RpYW8wMTk5_size_16_color_FFFFFF_t_70 3]

2.3 准备好8个必须的参数

①先拿到7个参数

appid：公众账号ID
    mch_id：商户号
    nonce_str：随机字符串
    out_trade_no：商户订单号
    out_refund_no：商户退款单号
    total_fee：订单金额
    refund_fee：退款金额

②根据上面的7个参数，得到第8个参数

sign：自己的签名。利用上面7个参数生成

2.4 发送去微信，让微信执行退款操作

2.5 源码

①RefundController

import java.util.Map;
    import java.util.SortedMap;
    import java.util.TreeMap;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import com.jc.util.wxPay.WXPayUtil;
    
    import controller.AuthUtil;
    import transfercontroller.CertHttpUtil;
    
    /**
     * @author: KOLO
     * @date:2018年12月29日 上午9:13:58
     * @version: 1.0 申请订单退款
     */
    @Controller
    @RequestMapping("/refund")
    public class RefundController {
    
    	/**
    	 * @Title: transfer
    	 * @Description: 申请订单退款
    	 * @param:
    	 * @return:
    	 */
    	@RequestMapping("/out")
    	public @ResponseBody String transfer(HttpServletRequest request, HttpServletResponse response) {
    		
    		// 1.0 拼凑微信退款需要的参数
    		String appid = AuthUtil.APPID; // 微信公众号的appid
    		String mch_id = AuthUtil.MCHID; // 商户号
    		String nonce_str = WXPayUtil.generateNonceStr(); // 生成随机数
    		String out_trade_no = "3cc7da01f4f54c3fbfbd0fd60b5559a6"; //商户订单号
    		String out_refund_no = "3cc7da01f4f54c3fbfbd0fd60b5559a6";//商户退款单号 
    		String total_fee = "1";//订单金额
    		String refund_fee = "1";//退款金额
    		 
    		 
    		// 2.0 生成map集合
    		SortedMap<String, String> packageParams = new TreeMap<String, String>();
    		packageParams.put("appid", appid); // 微信公众号的appid
    		packageParams.put("mch_id", mch_id); // 商务号
    		packageParams.put("nonce_str", nonce_str); // 随机生成后数字，保证安全性
    		packageParams.put("out_trade_no", out_trade_no); 
    		packageParams.put("out_refund_no", out_refund_no); 
    		packageParams.put("total_fee", total_fee); 
    		packageParams.put("refund_fee", refund_fee); 
    		
    		
    		try {
    			// 3.0 利用上面的参数，先去生成自己的签名
    			String sign = WXPayUtil.generateSignature(packageParams, AuthUtil.PATERNERKEY);
    
    			// 4.0 将签名再放回map中，它也是一个参数
    			packageParams.put("sign", sign);
    
    			// 5.0将当前的map结合转化成xml格式
    			String xml = WXPayUtil.mapToXml(packageParams);
    
    			// 6.0获取需要发送的url地址
    			String wxUrl = "https://api.mch.weixin.qq.com/secapi/pay/refund"; // 获取退款的api接口
    
    			System.out.println("发送前的xml为：" + xml);
    
    			// 7,向微信发送请求转账请求
    			String returnXml = CertHttpUtil.postData(wxUrl, xml, AuthUtil.MCHID, AuthUtil.CERTPATH);
    
    			System.out.println("返回的returnXml为:" + returnXml);
    
    			// 8，将微信返回的xml结果转成map格式
    			Map<String, String> returnMap = WXPayUtil.xmlToMap(returnXml);
    
    			if (returnMap.get("return_code").equals("SUCCESS")) {
    				// 退款成功
    				System.out.println("returnMap为:" + returnMap);
    
    			}
    
    			return returnXml;
    
    		} catch (Exception e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		return "error";
    	}
    
    }

②CertHttpUtil类

import java.io.File;
     import java.io.FileInputStream;
     import java.io.IOException;
    import java.io.InputStream;
    import java.security.KeyStore;
      
     import javax.net.ssl.SSLContext;
      
     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.conn.ssl.SSLContexts;
     import org.apache.http.entity.StringEntity;
     import org.apache.http.impl.client.CloseableHttpClient;
     import org.apache.http.impl.client.HttpClients;
     import org.apache.http.util.EntityUtils;
    import org.springframework.core.io.ClassPathResource;
    
    import controller.AuthUtil;
      
     /**
      * 获取微信apiclient_cert.p12证书
      *
      * @author zengwei
      * @email 15797630391@163.com
      * @date 2018年4月5日 下午4:49:36
      */ 
     public class CertHttpUtil {
      
         private static int socketTimeout = 10000;// 连接超时时间，默认10秒
         private static int connectTimeout = 30000;// 传输超时时间，默认30秒
         private static RequestConfig requestConfig;// 请求器的配置
         private static CloseableHttpClient httpClient;// HTTP请求器
      
         /**
          * 通过Https往API post xml数据
          *
          * @param url API地址
          * @param xmlObj 要提交的XML数据对象
         * @param mchId 商户ID
         * @param certPath 证书位置
          * @return
          */
         public static String postData(String url, String xmlObj, String mchId, String certPath) {
             // 加载证书
             try {
                 initCert(mchId, certPath);
             } 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;
         }
      
         /**
          * 加载证书
          *
          * @param mchId 商户ID
          * @param certPath 证书位置
          * @throws Exception
          */
         private static void initCert(String mchId, String certPath) throws Exception {
             // 证书密码，默认为商户ID
             String key = mchId;
             // 证书的路径
             String path = certPath;
             // 指定读取证书格式为PKCS12
             KeyStore keyStore = KeyStore.getInstance("PKCS12");
             // 读取本机存放的PKCS12证书文件  
             ClassPathResource cp = new ClassPathResource(AuthUtil.CERTPATH);
             InputStream instream = cp.getInputStream();
             try {
                 // 指定PKCS12的密码(商户ID)
                 keyStore.load(instream, key.toCharArray());
             } finally {
                 instream.close();
             }
             SSLContext sslcontext = SSLContexts.custom().loadKeyMaterial(keyStore, key.toCharArray()).build();
             SSLConnectionSocketFactory sslsf =
                     new SSLConnectionSocketFactory(sslcontext, new String[] {"TLSv1"}, null,
                             SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);
             httpClient = HttpClients.custom().setSSLSocketFactory(sslsf).build();
         }
     }

③AuthUtil类

import java.io.IOException;
    
    import javax.servlet.http.HttpServletRequest;
    
    import org.apache.http.HttpEntity;
    import org.apache.http.HttpResponse;
    import org.apache.http.client.ClientProtocolException;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.impl.client.DefaultHttpClient;
    import org.apache.http.util.EntityUtils;
    
    import net.sf.json.JSONObject;
    public class AuthUtil {
    	public static final String APPID = "商家APPID";
    	public static final String APPSECRET = "商家APPSECRET";
    	public static final String MCHID = "商家ID";
    	public static final String PATERNERKEY = "商家密钥";
    	public static final String CERTPATH = "商家证书在项目的存放路径";
    	
    	public static JSONObject doGetJson(String url) throws ClientProtocolException, IOException {
    		JSONObject jsonObject = null;
    		// 首先初始化HttpClient对象
    		DefaultHttpClient client = new DefaultHttpClient();
    		// 通过get方式进行提交
    		HttpGet httpGet = new HttpGet(url);
    		// 通过HTTPclient的execute方法进行发送请求
    		HttpResponse response = client.execute(httpGet);
    		// 从response里面拿自己想要的结果
    		HttpEntity entity = response.getEntity();
    		if (entity != null) {
    			String result = EntityUtils.toString(entity, "UTF-8");
    			jsonObject = jsonObject.fromObject(result);
    		}
    		// 把链接释放掉
    		httpGet.releaseConnection();
    		return jsonObject;
    	}
    	
    	/**
    	 * @Title: getRequestIp
    	 * @Description: 获取用户的ip地址
    	 * @param:
    	 * @return:
    	 */
    	public static String getRequestIp(HttpServletRequest request) {
    		String ip = request.getHeader("x-forwarded-for");
    		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
    			ip = request.getHeader("Proxy-Client-IP");
    		}
    		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
    			ip = request.getHeader("WL-Proxy-Client-IP");
    		}
    		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
    			ip = request.getRemoteAddr();
    		}
    		if (ip.indexOf(",") != -1) {
    			String[] ips = ip.split(",");
    			ip = ips[0].trim();
    		}
    		return ip;
    	}
    }

> 三，总结

这几天将微信的功能都做完了。发现去调微信的接口的时候，基本上都是这样的流程：

配置微信平台
    	||
    配置商家平台
    	||
    准备好必须的参数
    	||
    发送请求到微信
    	||
    获取返回的结果

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