微信统一支付 jsapi

public class UnifiedOrderRequest {

  @ApiModelProperty(value = "设备号")
  private String deviceInfo;
  @ApiModelProperty(value = "商品描述",required = true)
  private String body;
  @ApiModelProperty(value = "商品详情")
  private String detail;
  @ApiModelProperty(value = "附加数据")
  private String attach;
  @ApiModelProperty(value = "商户订单号",required = true)
  private String outTradeNo;
  @ApiModelProperty(value = "标价币种")
  private String feeType;
  @ApiModelProperty(value = "标价金额/分",required = true)
  private Integer totalFee;
  @ApiModelProperty(value = "终端IP",required = true)
  private String spbillCreateIp;
  @ApiModelProperty(value = "订单优惠标记")
  private String goodsTag;
  @ApiModelProperty(value = "交易类型",required = true)
  private String tradeType;
  @ApiModelProperty(value = "商品ID")
  private String productId;
  @ApiModelProperty(value = "指定支付方式")
  private String limitPay;
  @ApiModelProperty(value = "用户标识")
  private String openid;
  @ApiModelProperty(value = "电子发票入口开放标识")
  private String receipt;
  @ApiModelProperty(value = "场景信息")
  private String sceneInfo;

  private String appName;
  private Integer userId;

}

 public String unifiedOrders(UnifiedOrderRequest unifiedOrderRequest) {

    String appId ="";//需要填写
    String mchId = "";//需要填写
    String appKey = "";//用来做加密的
    String nonceStr = generateBillNoService.generateRandomString(12);//随机字符串
    String notifyUrl = "";//支付结果回调地址
    SortedMap<String, Object> sortedMap = new TreeMap<>();

    sortedMap.put("appid", appId);
    sortedMap.put("mch_id", mchId);
    sortedMap.put("nonce_str", nonceStr);
    sortedMap.put("body", unifiedOrderRequest.getBody());
    sortedMap.put("out_trade_no", unifiedOrderRequest.getOutTradeNo());
    sortedMap.put("total_fee", unifiedOrderRequest.getTotalFee().toString());
    sortedMap.put("spbill_create_ip", unifiedOrderRequest.getSpbillCreateIp());
    sortedMap.put("notify_url", notifyUrl);
    sortedMap.put("trade_type", unifiedOrderRequest.getTradeType());
    sortedMap.put("openid", unifiedOrderRequest.getOpenid());
    String sign = weiXinProxy.createSign("utf-8", sortedMap, appKey);//做签名
    sortedMap.put("sign", sign);

    Map<String, String> payResultMap = weiXinProxy.unifiedOrder(sortedMap);
　　　//进行校验
    if (weiXinProxy.checkResultInfo(payResultMap, appKey).getCode() != 0) {
      return weiXinProxy.checkResultInfo(payResultMap, appKey).getMessage();
    }

    return payResultMap.get("prepay_id");
  }　

　给相关数据做签名

public String createSign(String characterEncoding, SortedMap<String, Object> parameters, String apiKey) {
    StringBuffer sb = new StringBuffer();
    Set es = parameters.entrySet();
    Iterator it = es.iterator();
    while (it.hasNext()) {
      Map.Entry entry = (Map.Entry) it.next();
      String k = (String) entry.getKey();
      Object v = entry.getValue();
      if (null != v && !"".equals(v) && !"sign".equals(k) && !"key".equals(k)) {
        sb.append(k + "=" + v + "&");
      }
    }
    sb.append("key=" + apiKey);
    String sign = MD5Encode(sb.toString(), characterEncoding).toUpperCase();
    return sign;
  }

　　MD5加密

public static String MD5Encode(String origin, String charsetname) {
    String resultString = null;
    try {
      resultString = new String(origin);
      MessageDigest md = MessageDigest.getInstance("MD5");
      if (charsetname == null || "".equals(charsetname))
        resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
      else
        resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
    } catch (Exception exception) {
    }
    return resultString;
  }

　　支付结果校验

public DefaultResponse checkResultInfo(Map<String, String> payResultMap, String secrectkey) {
    SortedMap<String, Object> resultMap = new TreeMap<>();
    for (String key : payResultMap.keySet()) {
      if (key.equals("sign")) {
        continue;
      } else {
        resultMap.put(key, payResultMap.get(key));
      }
    }
    DefaultResponse response = new DefaultResponse(0, "SUCCESS");

    if (payResultMap.get("return_code") == null || !payResultMap.get("return_code").equals("SUCCESS")) {
      response.setCode(10001);
      response.setMessage(payResultMap.get("return_msg"));
    } else if (payResultMap.get("result_code") == null || !payResultMap.get("result_code").equals("SUCCESS")) {
      response.setCode(10001);
      response.setMessage(payResultMap.get("err_code_des"));
    } else if (payResultMap.get("sign") == null || !payResultMap.get("sign").equals(createSign("utf-8", resultMap, secrectkey))) {
      response.setCode(10001);
      response.setMessage("支付失败_数据错误");
    }
    log.info(response);
    return response;
  }

　　调用微信接口

public Map<String, String> unifiedOrder(@RequestBody SortedMap<String, Object> request) {
    RestTemplate restTemplate = new RestTemplate();
    String requestUri = Constant.WX_PAY_URL;
    Map<String, String> map = new HashMap<>();
    try {
      map = doXMLParse(new String(restTemplate.postForObject(requestUri, getRequestXml(request), String.class).getBytes("ISO-8859-1"), "UTF-8"));//防止中文乱码
    } catch (Exception e) {
      log.info(e.getMessage());
    }
    return map;
  }

　　生成xml

public String getRequestXml(SortedMap<String, Object> parameters) {
  StringBuffer sb = new StringBuffer();
  sb.append("<xml>");
  Set es = parameters.entrySet();
  Iterator it = es.iterator();
  while (it.hasNext()) {
    Map.Entry entry = (Map.Entry) it.next();
    String key = (String) entry.getKey();
    String value = (String) entry.getValue();
    if ("attach".equalsIgnoreCase(key) || "body".equalsIgnoreCase(key) || "sign".equalsIgnoreCase(key)) {
      sb.append("<" + key + ">" + "<![CDATA[" + value + "]]></" + key + ">");
    } else {
      sb.append("<" + key + ">" + value + "</" + key + ">");
    }
  }
  sb.append("</xml>");
  try {
    return new String(sb.toString().getBytes(), "ISO8859-1");
  } catch (UnsupportedEncodingException e) {
    e.printStackTrace();
    return null;
  }
}

解析返回的xml

 public Map<String, String> doXMLParse(String strxml) throws Exception {
    strxml = strxml.replaceFirst("encoding=\".*\"", "encoding=\"UTF-8\"");

    if (null == strxml || "".equals(strxml)) {
      return null;
    }
    Map<String, String> map = new HashMap();

    InputStream in = new ByteArrayInputStream(strxml.getBytes("UTF-8"));
    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);
      }
      map.put(k, v);
    }
    //关闭流
    in.close();
    return map;
  }

支付结果回调接口

public String callBackWeiXinPay(String xml) {
    log.info(xml);
    Map<String, String> map = new HashMap<>();
    try {
      if (xml == null)
        return "FAIL";
      map = weiXinProxy.doXMLParse(xml);
      //有订单号 代表成功
      if (map.get("out_trade_no") != null) {

        String appKey = "";
        //签名验证
        DefaultResponse defaultResponse = weiXinProxy.checkResultInfo(map, appKey);
        //验证回调结果 （订单金额和返回的金额是否相等）写功能
      }
  　　//通知微信
      return "<xml><return_code><![CDATA[SUCCESS]]></return_code><return_msg><![CDATA[OK]]></return_msg></xml>";
    } catch (Exception e) {
      e.printStackTrace();
      return "FAIL";
    }
  }

原文地址：https://www.cnblogs.com/water-dream/p/10812020.html