微信小程序登录流程

• 前端获取 jsCode
• 携带 jsCode 调用后端登录接口
• 后端通过 jsCode + appId + appSecret + grant_type请求微信,获取到 openId.

https://api.weixin.qq.com/sns/jscode2session?appid=APPID&secret=SECRET&js_code=JSCODE&grant_type=authorization_code

jsCode获取openId

private String code2Session(String jsCode) {
    // https://api.weixin.qq.com/sns/jscode2session?appid=APPID&secret=SECRET&js_code=JSCODE&grant_type=authorization_code
    String uri = miniprogramProperty.getCode2SessionUri() + "?appid=" + miniprogramProperty.getAppId()
            + "&secret=" + miniprogramProperty.getAppSecret() + "&js_code=" + jsCode + "&grant_type=authorization_code";
    Mono<String> code2SessionResultMono = WebClient.create()
            .get().uri(uri).retrieve().bodyToMono(String.class);
    String result = code2SessionResultMono.block();
    log.debug("code2SessionResultMono: {}", result);
    Code2SessionResult code2SessionResult;
    try {
        code2SessionResult = objectMapper.readValue(result, Code2SessionResult.class);
    } catch (JsonProcessingException e) {
        log.error("小程序结果解析失败,result={}", result);
        throw new ServiceException("小程序登录结果解析失败");
    }

    if (code2SessionResult == null) {
        log.error("code2SessionResult is null");
        throw new ServiceException("小程序登录失败1");
    }
    if (code2SessionResult.errcode() != null && (!"0".equals(code2SessionResult.errcode()))) {
        log.error("code2SessionResult errcode: {}, msg: {}", code2SessionResult.errcode(), code2SessionResult.errmsg());
        throw new ServiceException("小程序登录失败,code=" + code2SessionResult.errcode());
    }
    return code2SessionResult.openid;

}
~~~`