java微信小程序支付-回调（Jsapi-APIv3）
一、接入前准备，按照这个文档准备
准备： 接入前准备-小程序支付 | 微信支付商户平台文档中心
准备好了就可以获得(第二点里需要的参数)：
参数1 商户号 merchantId:xxxxxx(全是数字)
参数2 商户APIV3密钥 apiV3key：xxxxxxx（32位字母数字大小写串，开发自己准备的）
参数3 商户证书序列号 merchantSerialNumber：xxxxx
查看方式：微信支付证书序列号在哪里看（v3商户证书序列号在哪里查找）-李飞SEO
参数4 商户API私钥路径 privateKeyPath：apiclient_key.pem的文件路径
---------------------Native (二维码)支付下单，前四个就够了，5是用于Jsapi支付----------------
参数5 国密的微信支付平台证书路径(X509文件) wechatPayCertificatePath:wechatpay_xxxx.pem()
这个文件找了好久，最后试用下边这个工具下下来可以用GitHub - wechatpay-apiv3/CertificateDownloader: Java 微信支付 APIv3 平台证书的命令行下载工具
二、支付代码接入
支付-官网文档：https://pay.weixin.qq.com/wiki/doc/api/wxa/wxa_api.php?chapter=7_7
微信给apiv3做了个maven包，终于像个样子了，结果我发现里边native支付例子虽然完整，但是第一大点里的1-5个参数完全不知道怎么给，jsapi参数同理，我是的东拼西凑凑齐了。maven包文档
贴一个jsapi的调用例子，小程序端唤起支付用它就够了，这是在官方的例子基础上补全了：
import com.alibaba.fastjson.JSONObject;
import com.wechat.pay.java.core.Config;
import com.wechat.pay.java.core.RSAConfig;
import com.wechat.pay.java.core.exception.HttpException;
import com.wechat.pay.java.core.exception.MalformedMessageException;
import com.wechat.pay.java.core.exception.ServiceException;
import com.wechat.pay.java.service.payments.jsapi.JsapiServiceExtension;
import com.wechat.pay.java.service.payments.jsapi.model.CloseOrderRequest;
import com.wechat.pay.java.service.payments.jsapi.model.Payer;
import com.wechat.pay.java.service.payments.jsapi.model.PrepayRequest;
import com.wechat.pay.java.service.payments.jsapi.model.PrepayWithRequestPaymentResponse;
import com.wechat.pay.java.service.payments.jsapi.model.QueryOrderByIdRequest;
import com.wechat.pay.java.service.payments.jsapi.model.QueryOrderByOutTradeNoRequest;
import com.wechat.pay.java.service.payments.model.Transaction;
import com.wechat.pay.java.service.payments.jsapi.model.Amount;
import lombok.extern.slf4j.Slf4j;
@Slf4j
public class JsapiDemoService {
public static String merchantId = "1xxxx";
// public static String privateKeyPath = "";
public static String merchantSerialNumber = "xxxx";
public static String wechatPayCertificatePath = "";
public static com.wechat.pay.java.service.payments.jsapi.JsapiServiceExtension service;
public static PrepayWithRequestPaymentResponse createWxJsapOrder(String certificatePath, String keyPath, JsapiReq cliReq) {
String method = Thread.currentThread().getStackTrace()[1].getMethodName();
// 使用自动更新平台证书的RSA配置
// 一个商户号只能初始化一个配置，否则会因为重复的下载任务报错
Config config =
new RSAConfig.Builder()
.merchantId(merchantId)
// 使用 com.wechat.pay.java.core.util 中的函数从本地文件中加载商户私钥，商户私钥会用来生成请求的签名
.privateKeyFromPath(keyPath)
.merchantSerialNumber(merchantSerialNumber)
.wechatPayCertificatesFromPath(certificatePath)
.build();
// 构建service
JsapiServiceExtension service = new JsapiServiceExtension.Builder().config(config).build();
// request.setXxx(val)设置所需参数，具体参数可见Request定义
PrepayRequest request = new PrepayRequest();
Payer payer = new Payer();
payer.setOpenid(cliReq.getOpenid());
request.setPayer(payer);
Amount amount = new Amount();
amount.setTotal(10);//订单总金额，单位为分
request.setAmount(amount);
request.setAppid("wxddddxxxxxx");
request.setMchid("1xxxx");
request.setDescription("ms");
request.setNotifyUrl("https://xxx.net/callBackr");
//request.setOutTradeNo("out_trade_no_1");
request.setOutTradeNo(cliReq.getOutTradeNo());
// 调用下单方法，得到应答
try {
// ... 调用接口
PrepayWithRequestPaymentResponse response = service.prepayWithRequestPayment(request);
// 使用微信扫描 code_url 对应的二维码，即可体验Native支付
System.out.println(JSONObject.toJSON(response));
return response;
} catch (HttpException e) { // 发送HTTP请求失败
// 调用e.getHttpRequest()获取请求打印日志或上报监控，更多方法见HttpException定义
log.error(method, e);
} catch (ServiceException e) { // 服务返回状态小于200或大于等于300，例如500
// 调用e.getResponseBody()获取返回体打印日志或上报监控，更多方法见ServiceException定义
log.error(method, e);
} catch (MalformedMessageException e) { // 服务返回成功，返回体类型不合法，或者解析返回体失败
// 调用e.getMessage()获取信息打印日志或上报监控，更多方法见MalformedMessageException定义
log.error(method, e);
} catch (Exception e) { // 服务返回成功，返回体类型不合法，或者解析返回体失败
// 调用e.getMessage()获取信息打印日志或上报监控，更多方法见MalformedMessageException定义
log.error(method, e);
}
return new PrepayWithRequestPaymentResponse();
}
/** 关闭订单 */
public static void closeOrder() {
CloseOrderRequest request = new CloseOrderRequest();
// 调用request.setXxx(val)设置所需参数，具体参数可见Request定义
// 调用接口
service.closeOrder(request);
}
/** JSAPI支付下单，并返回JSAPI调起支付数据 */
public static PrepayWithRequestPaymentResponse prepayWithRequestPayment() {
PrepayRequest request = new PrepayRequest();
// 调用request.setXxx(val)设置所需参数，具体参数可见Request定义
// 调用接口
return service.prepayWithRequestPayment(request);
}
/** 微信支付订单号查询订单 */
public static Transaction queryOrderById() {
QueryOrderByIdRequest request = new QueryOrderByIdRequest();
// 调用request.setXxx(val)设置所需参数，具体参数可见Request定义
// 调用接口
return service.queryOrderById(request);
}
/** 商户订单号查询订单 */
public static Transaction queryOrderByOutTradeNo() {
QueryOrderByOutTradeNoRequest request = new QueryOrderByOutTradeNoRequest();
// 调用request.setXxx(val)设置所需参数，具体参数可见Request定义
// 调用接口
return service.queryOrderByOutTradeNo(request);
}
}
补下JsapiReq 的定义
public class JsapiReq implements Serializable {
private static final long serialVersionUID = 1L;
private String openid;
private String outTradeNo;
}另外记一下java/spring/srpingboot里resource文件读取路径的方法
String userDir = System.getProperty("user.dir");
String certificatePath = userDir + "/src/main/resources/cert/wechatpay_xxx.pem";
String keyPath = userDir + "/src/main/resources/cert/apiclient_xxxxkey.pem";三、支付回调
支付回调-官网文档：微信支付-开发者文档
代码
@PostMapping(value = "/callBack")
public Map<String, String> callBack(@RequestBody JSONObject jsonObject) {
String method = Thread.currentThread().getStackTrace()[1].getMethodName();
try {
String key = WxNativePayProxy.getWxV3Key();
String json = jsonObject.toString();
String associated_data = (String) JSONUtil.getByPath(JSONUtil.parse(json), "resource.associated_data");
String ciphertext = (String) JSONUtil.getByPath(JSONUtil.parse(json), "resource.ciphertext");
String nonce = (String) JSONUtil.getByPath(JSONUtil.parse(json), "resource.nonce");
String decryptData = new AesUtil(key.getBytes(StandardCharsets.UTF_8)).decryptToString(associated_data.getBytes(StandardCharsets.UTF_8), nonce.getBytes(StandardCharsets.UTF_8), ciphertext);
//验签成功
JSONObject decryptDataObj = JSONObject.parseObject(decryptData, JSONObject.class);
//decryptDataObj 为解码后的obj，其内容如下。之后便是验签成功后的业务处理
//{
// "sp_appid": "wx8888888888888888",
// "sp_mchid": "1230000109",
// "sub_appid": "wxd678efh567hg6999",
// "sub_mchid": "1900000109",
// "out_trade_no": "1217752501201407033233368018",
// "trade_state_desc": "支付成功",
// "trade_type": "MICROPAY",
// "attach": "自定义数据",
// "transaction_id": "1217752501201407033233368018",
// "trade_state": "SUCCESS",
// "bank_type": "CMC",
// "success_time": "2018-06-08T10:34:56+08:00",
// ...
// "payer": {
// "openid": "oUpF8uMuAJO_M2pxb1Q9zNjWeS6o"
// },
// "scene_info": {
// "device_id": "013467007045764"
// }
//}
}catch (Exception e){
log.info("{} ,parms{}, 异常:", method, jsonObject.toJSONString(), e);
}
Map<String, String> res = new HashMap<>();
res.put("code", "SUCCESS");
res.put("message", "成功");
return res;
}其中有用到微信解码工具类:AesUtil
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.GCMParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class AesUtil{
static final int KEY_LENGTH_BYTE = 32;
static final int TAG_LENGTH_BIT = 128;
private final byte[] aesKey;
public AesUtil(byte[] key) {
if (key.length != KEY_LENGTH_BYTE) {
throw new IllegalArgumentException("无效的ApiV3Key，长度必须为32个字节");
}
this.aesKey = key;
}
public String decryptToString(byte[] associatedData, byte[] nonce, String ciphertext)
throws GeneralSecurityException, IOException {
try {
Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
SecretKeySpec key = new SecretKeySpec(aesKey, "AES");
GCMParameterSpec spec = new GCMParameterSpec(TAG_LENGTH_BIT, nonce);
cipher.init(Cipher.DECRYPT_MODE, key, spec);
cipher.updateAAD(associatedData);
return new String(cipher.doFinal(Base64.getDecoder().decode(ciphertext)), "utf-8");
} catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
throw new IllegalStateException(e);
} catch (InvalidKeyException | InvalidAlgorithmParameterException e) {
throw new IllegalArgumentException(e);
}
}
}