Java 微信企业付款到个人银行卡-调用获取RSA公钥API

    **一、使用微信sdk的Xml转换工具类**

 import org.w3c.dom.Document;

    
  
    
 import javax.xml.XMLConstants;
    
 import javax.xml.parsers.DocumentBuilder;
    
 import javax.xml.parsers.DocumentBuilderFactory;
    
 import javax.xml.parsers.ParserConfigurationException;
    
  
    
 /** * 2018/7/3
    
  */
    
 public final class WXPayXmlUtil {
    
     public static DocumentBuilder newDocumentBuilder() throws ParserConfigurationException {
    
     DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
    
     documentBuilderFactory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
    
     documentBuilderFactory.setFeature("http://xml.org/sax/features/external-general-entities", false);
    
     documentBuilderFactory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
    
     documentBuilderFactory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
    
     documentBuilderFactory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
    
     documentBuilderFactory.setXIncludeAware(false);
    
     documentBuilderFactory.setExpandEntityReferences(false);
    
  
    
     return documentBuilderFactory.newDocumentBuilder();
    
     }
    
  
    
     public static Document newDocument() throws ParserConfigurationException {
    
     return newDocumentBuilder().newDocument();
    
     }
    
 }

    二、进行携带证书的http的请求，获取公钥

  
    
 import java.io.*;
    
 import java.security.KeyStore;
    
 import java.security.MessageDigest;
    
 import java.security.PublicKey;
    
 import java.security.SecureRandom;
    
 import java.util.*;
    
  
    
 import javax.net.ssl.SSLContext;
    
 import javax.xml.transform.OutputKeys;
    
 import javax.xml.transform.Transformer;
    
 import javax.xml.transform.TransformerFactory;
    
 import javax.xml.transform.dom.DOMSource;
    
 import javax.xml.transform.stream.StreamResult;
    
  
    
 import org.apache.http.HttpEntity;
    
 import org.apache.http.client.methods.CloseableHttpResponse;
    
 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 org.apache.logging.log4j.LogManager;
    
 import org.apache.logging.log4j.Logger;
    
  
    
 public class HttpClientSSL {
    
     Logger log = LogManager.getLogger(HttpClientSSL.class);
    
  
    
     private static String payUrl = "https://fraud.mch.weixin.qq.com/risk/getpublickey";
    
     //商户key
    
     private static String KEY = "xxxxxxxxxx";
    
     //商户mch_id
    
     private static String mchId = "xxxxxxxxx";
    
  
    
     public static void main(String[] args) throws Exception {
    
     Map<String, String> parameterMap = new HashMap<>();
    
     parameterMap.put("mch_id", mchId);
    
     parameterMap.put("nonce_str", generateNonceStr());
    
     try{
    
  
    
         parameterMap.put("sign_type", "MD5");
    
         parameterMap.put("sign", HttpClientSSL.generateSignature(parameterMap,KEY,"MD5"));
    
         //要以xml格式传递
    
         String postDataXML = HttpClientSSL.mapToXml(parameterMap);
    
         String result = HttpClientSSL.wxRefundLink(postDataXML, mchId );
    
  
    
         System.out.println(result);
    
     }catch (Exception e){
    
         e.printStackTrace();
    
     }
    
     }
    
  
    
     /** * 将Map转换为XML格式的字符串
    
      * * @param data Map类型数据
    
      * @return XML格式的字符串
    
      * @throws Exception
    
      */
    
     public static String mapToXml(Map<String, String> data) throws Exception {
    
     org.w3c.dom.Document document = WXPayXmlUtil.newDocument();
    
     org.w3c.dom.Element root = document.createElement("xml");
    
     document.appendChild(root);
    
     for (String key: data.keySet()) {
    
         String value = data.get(key);
    
         if (value == null) {
    
             value = "";
    
         }
    
         value = value.trim();
    
         org.w3c.dom.Element filed = document.createElement(key);
    
         filed.appendChild(document.createTextNode(value));
    
         root.appendChild(filed);
    
     }
    
     TransformerFactory tf = TransformerFactory.newInstance();
    
     Transformer transformer = tf.newTransformer();
    
     DOMSource source = new DOMSource(document);
    
     transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
    
     transformer.setOutputProperty(OutputKeys.INDENT, "yes");
    
     StringWriter writer = new StringWriter();
    
     StreamResult result = new StreamResult(writer);
    
     transformer.transform(source, result);
    
     String output = writer.getBuffer().toString(); //.replaceAll("\n|\r", "");
    
     try {
    
         writer.close();
    
     }
    
     catch (Exception ex) {
    
     }
    
     return output;
    
     }
    
  
    
     private static final String SYMBOLS = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    
  
    
     private static final Random RANDOM = new SecureRandom();
    
     /** * 获取随机字符串 Nonce Str
    
      * * @return String 随机字符串
    
      */
    
     public static String generateNonceStr() {
    
     char[] nonceChars = new char[32];
    
     for (int index = 0; index < nonceChars.length; ++index) {
    
         nonceChars[index] = SYMBOLS.charAt(RANDOM.nextInt(SYMBOLS.length()));
    
     }
    
     return new String(nonceChars);
    
     }
    
     public static String generateSignature(Map<String, String> data, String key, String signType) throws Exception {
    
     Set<String> keySet = data.keySet();
    
     String[] keyArray = keySet.toArray(new String[keySet.size()]);
    
     Arrays.sort(keyArray);
    
     StringBuilder sb = new StringBuilder();
    
     for (String k : keyArray) {
    
         if (k.equals("sign")) {
    
             continue;
    
         }
    
         if (data.get(k).trim().length() > 0) // 参数值为空，则不参与签名
    
             sb.append(k).append("=").append(data.get(k).trim()).append("&");
    
     }
    
     sb.append("key=").append(key);
    
     if ("MD5".equals(signType)) {
    
         return MD5(sb.toString()).toUpperCase();
    
     }
    
     else {
    
         throw new Exception(String.format("Invalid sign_type: %s", signType));
    
     }
    
     }
    
     /** * 生成 MD5
    
      * * @param data 待处理数据
    
      * @return MD5结果
    
      */
    
     public static String MD5(String data) throws Exception {
    
     java.security.MessageDigest md = MessageDigest.getInstance("MD5");
    
     byte[] array = md.digest(data.getBytes("UTF-8"));
    
     StringBuilder sb = new StringBuilder();
    
     for (byte item : array) {
    
         sb.append(Integer.toHexString((item & 0xFF) | 0x100).substring(1, 3));
    
     }
    
     return sb.toString().toUpperCase();
    
     }
    
  
    
     private static String  wxRefundLink(String postDataXML,String mch_id) throws Exception{
    
     CloseableHttpClient httpClient = null;
    
     CloseableHttpResponse httpResponse = null;
    
     try{
    
         //获取微信支付api证书
    
         KeyStore keyStore = getCertificate(mch_id);
    
         SSLContext sslContext = SSLContexts.custom().loadKeyMaterial(keyStore, mch_id.toCharArray()).build();
    
         SSLConnectionSocketFactory sslf = new SSLConnectionSocketFactory(sslContext);
    
         httpClient = HttpClients.custom().setSSLSocketFactory(sslf).build();
    
         HttpPost httpPost = new HttpPost(payUrl);
    
  
    
         StringEntity reqEntity = new StringEntity(postDataXML);
    
         // 设置类型
    
         reqEntity.setContentType("application/x-www-form-urlencoded");
    
         httpPost.setEntity(reqEntity);
    
         String result = null;
    
         httpResponse = httpClient.execute(httpPost);
    
         HttpEntity httpEntity = httpResponse.getEntity();
    
         result = EntityUtils.toString(httpEntity, "UTF8");
    
         EntityUtils.consume(httpEntity);
    
         return result;
    
     }finally {//关流
    
         httpClient.close();
    
         httpResponse.close();
    
     }
    
  
    
     }
    
  
    
     /** * * @description: 获取微信支付api证书
    
      */
    
     private static KeyStore getCertificate(String mch_id){
    
     //try-with-resources 关流
    
     try (FileInputStream inputStream = new FileInputStream(new File("C:\ Users\ Administrator\ Desktop\ apiclient_cert.p12"))) {//证书文件位置
    
         KeyStore keyStore = KeyStore.getInstance("PKCS12");
    
         keyStore.load(inputStream, mch_id.toCharArray());
    
         return keyStore;
    
     } catch (Exception e) {
    
         throw new RuntimeException(e.getMessage(), e);
    
     }
    
     }
    
 }