最近一段时间接触了小程序以及其他一些相关的支付宝支付的对接，看了很长时间的开发文档。

对此也有自己的一些看法，在此记录。

具体的一些链接：

小程序支付接入：https://docs.alipay.com/mini/introduce/pay

接口相关参数文档：https://docs.open.alipay.com/api_1/alipay.trade.create/

生成RSA密钥工具：https://docs.open.alipay.com/291/105971/

样式：

一些前置工作在此不多说了。（审核申请等）

支付流程：

首先下载工具获得私钥和公钥。

拷贝商户应用公钥。

登录支付宝，右上角的账号管理中 设置应用公钥（需要绑定手机号以及一系列审核）

然后在代码中使用的全是支付宝公钥，不是应用公钥

导入pom依赖：

  <dependency>        <groupId>com.alipay.sdk</groupId>        <artifactId>alipay-sdk-java</artifactId>        <version>3.3.87.ALL</version>  </dependency>

贴一段主要代码：

/** * @Author xty * @Description * @Date 18:03 2018/10/26 */@Service("payService")@Transactional(rollbackFor = Exception.class, value = "transactionManager")public class PayServiceImpl implements PayService {    /**     * 商户appid     */    public static String APPID = "";    /**     * 请求网关地址     */    public static String URL = "https://openapi.alipay.com/gateway.do";    /**     * 私钥     */     public static String RSA_PRIVATE_KEY = "";    /**     * 支付宝公钥     */    public static String ALIPAY_PUBLIC_KEY ="";    /**     * RSA2     */    public static String SIGNTYPE = "RSA2";    /**     * 返回格式     */    public static String FORMAT = "json";    /**     * 编码     */    public static String CHARSET = "UTF-8";    @Override    public AlipayTradeCreateResponse pay(AlipayRequest req) {        AlipayClient alipayClient = new                DefaultAlipayClient(URL, APPID, RSA_PRIVATE_KEY, FORMAT, CHARSET,                ALIPAY_PUBLIC_KEY, SIGNTYPE);        AlipayTradeCreateRequest request = new AlipayTradeCreateRequest ();        request.setBizContent("{"+                ""out_trade_no""+":"+"""+IdUtil.nextId()+"""+","+                ""total_amount""+":"+"""+req.getTotalAmount()+"""+","+                ""subject""+":"+"""+req.getSubject()+"""+","+                ""buyer_id""+":"+"""+req.getBuyerId()+"""+                "}"        );        AlipayTradeCreateResponse response = null;        try {            response = alipayClient.execute(request);        } catch (AlipayApiException e) {            e.printStackTrace();        }        return response;    }}

上面具体参数根据自己公司的来填写。

setBizContent中的业务参数可以看文档根据自己需要来传。

返回参数：

之后前端拿到参数进行接口调用。

my.tradePay({tradeNO: '2017111521001104105336677922',  success: function(res) {my.alert(res.resultCode);},fail: function(res) {          my.alert(res.resultCode);       },});

关于buyer_id获取（userid）

相关授权：

前端获取auth_code，传给后端后返回userid和token，后端进行相关一系列业务处理。（token存入redis中）

/** * @Author xty * @Description * @Date 18:03 2018/10/26 */@Service("payService")@Transactional(rollbackFor = Exception.class, value = "transactionManager")public class PayServiceImpl implements PayService {    @Autowired    private ICache iCache;    @Autowired    private UcUserRelationService ucUserRelationService;    @Override    public AlipaySystemOauthTokenResponse oauth(AliOauthTokenRequest request) throws AlipayApiException {        AlipayClient alipayClient = new                DefaultAlipayClient(AlipayConstant.URL, AlipayConstant.APPID, AlipayConstant.RSA_PRIVATE_KEY, AlipayConstant.FORMAT, AlipayConstant.CHARSET,                AlipayConstant.ALIPAY_PUBLIC_KEY, AlipayConstant.SIGNTYPE);        AlipaySystemOauthTokenRequest alipaySystemOauthTokenRequest = new AlipaySystemOauthTokenRequest();        alipaySystemOauthTokenRequest.setGrantType(request.getGrantType());        alipaySystemOauthTokenRequest.setCode(request.getCode());        alipaySystemOauthTokenRequest.setRefreshToken(request.getRefreshToken());        AlipaySystemOauthTokenResponse response = alipayClient.execute(alipaySystemOauthTokenRequest);        if (response.isSuccess()) {            String userId = response.getUserId();            String accessToken = response.getAccessToken();            //1.存入关系表            UcUserRelation ucUserRelation = new UcUserRelation();            ucUserRelation.setId(IdUtil.nextId());            ucUserRelation.setUserId(request.getLoginUserId());            ucUserRelation.setObjType(UcUserRelationObjType.ALIPAY.value);            ucUserRelation.setObjId(Long.parseLong(userId));            ucUserRelation.setObjNo(request.getCode());            ucUserRelation.setCreateBy(Long.parseLong("0"));            ucUserRelation.setGmtCreate(new Date());            ucUserRelation.setModifyBy(Long.parseLong("0"));            ucUserRelation.setGmtModify(new Date());            ucUserRelationService.insertSelective(ucUserRelation);            //2.token存入redis            iCache.setString(userId,accessToken,30,TimeUnit.MINUTES);            return response;        } else {            return response;        }    }}