微信退款开发需要的步骤比较多，首先是按照官方文档生成证书，下载下来是一个zip。有时候会很疑惑，这个证书怎么用？实际上呢，就是发送接口的时候带上证书就可了。看一个具体的例子吧，以JSAPI微信退款为例。1、首先是发起退款申请因为每次发起退款请求，都要带上证书，如果直接从证书文件读取内容，速度很慢，因此将证书内容存放于内存中。大致如下：
@Getter
@Configuration
public class WxConfig {
/**
* 微信支付，证书存放父路径 证书名称：商户id_cert.p12 商户id_cert.pem 商户id_key.pem
*/
@Value("${wx.apiCertLocation}")
private String apiCertLocation;
/**
* 从 商户id_cert.p12文件读取内容，放入字节数组。(不要每次都从io中获取数据，太慢)
*/
private byte [] certData;
/**
* 将商户id_cert.p12文件内容转换成流
* @return
*/
public InputStream getCertStream() throws IOException {
if(certData==null||certData.length==0){
InputStream certStream = new FileInputStream(apiCertLocation mchId "_cert.p12");
this.certData = IOUtils.toByteArray(certStream);
certStream.close();
}
return new ByteArrayInputStream(this.certData);
}
}
下面就是发送带证书的请求了：
InputStream certStream = wxConfig.getCertStream();
String xmlResult = requestWithApiCert(REFUND_URL,xmlStr,mchId(),certStream);
certStream.close();
具体的工具类：
/**
* 微信支付 带API证书的请求
* @return
* @throws Exception
*/
public static String requestWithApiCert(String url, String data, String mchId,InputStream certStream) throws Exception {
BasicHttpClientConnectionManager connManager;
// 证书
char[] password = mchId.toCharArray();
KeyStore ks = KeyStore.getInstance("PKCS12");
ks.load(certStream, password);
// 实例化密钥库 & 初始化密钥工厂
KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
kmf.init(ks, password);
// 创建 SSLContext
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(kmf.getKeyManagers(), null, new SecureRandom());
SSLConnectionSocketFactory sslConnectionSocketFactory = new SSLConnectionSocketFactory(
sslContext,
new String[]{"TLSv1"},
null,
new DefaultHostnameVerifier());
connManager = new BasicHttpClientConnectionManager(
RegistryBuilder.<ConnectionSocketFactory>create()
.register("http", PlainConnectionSocketFactory.getSocketFactory())
.register("https", sslConnectionSocketFactory)
.build(),
null,
null,
null
);
HttpClient httpClient = HttpClientBuilder.create()
.setConnectionManager(connManager)
.build();
HttpPost httpPost = new HttpPost(url);
RequestConfig requestConfig = RequestConfig.custom().build();
httpPost.setConfig(requestConfig);
StringEntity postEntity = new StringEntity(data, "UTF-8");
httpPost.addHeader("Content-Type", "text/xml");
httpPost.setEntity(postEntity);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
return EntityUtils.toString(httpEntity, "UTF-8");
}
微信退款回调中，有一个req_info字段，需要解密才可以使用:
/**
* 注意此方法 如果报错：Illegal key size or default parameters
一般需要到oracle官网下载local_policy.jar US_export_policy.jar
包进行替换，路径：jdk安装路径/jre/lib/security
* @param reqInfo
* @param apiKey
* @return reqInfo的xml字符串
* @throws Exception
*/
public static String getReqInfoXml(String reqInfo,String apiKey) throws Exception{
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
MessageDigest md5 = MessageDigest.getInstance("MD5");
md5.update(apiKey.getBytes());
String keyMd5String = (new BigInteger(1, md5.digest())).toString(16).toLowerCase();
SecretKeySpec key = new SecretKeySpec(keyMd5String.getBytes(), "AES");
cipher.init(2, key);
return new String(cipher.doFinal(Base64.decodeBase64(reqInfo)));
}
