1.业务描述

1.小程序用户登录

2.用户入库

3.返回token给小程序用户

4.授权小程序昵称和头像

2.实现流程

参考官方流程图：

3.主要代码

前端：

后端： 

/*** 小程序登录获取接口访问token,主入口** @param jsCode 小程序jsCode* @return 返回token给前端*/
@ResponseBody
@GetMapping("code2Session")
@ApiOperation("小程序-code2Session(获取openid)")
public ResponseData code2Session(String jsCode) {log.info("小程序用户登录，code2Session(获取openid)");String code2SessionUrl = "https://api.weixin.qq.com/sns/jscode2session?appid=" + appid + "&secret=" + secret + "&js_code=" + jsCode + "&grant_type=authorization_code";String content = restTemplate.getForEntity(code2SessionUrl, String.class).getBody();String openid = JSON.parseObject(content).get("openid").toString();String unionid = JSON.parseObject(content).get("unionid").toString();if (StrUtil.isEmpty(openid)) {return new ErrorResponseData("openid不能为空");}if (StrUtil.isEmpty(unionid)) {return new ErrorResponseData("unionid不能为空");}Map map = new TreeMap<>();QueryWrapper queryWrapper = new QueryWrapper<>();queryWrapper.eq("user_union", unionid);User user_union = userService.getOne(queryWrapper);QueryWrapper queryWrapper1 = new QueryWrapper<>();queryWrapper1.eq("user_mini_wx ", openid);User user_mini = userService.getOne(queryWrapper1);//判断此用户是否存在数据库中if (user_mini == null) {User user1;log.info("小程序用户登录，当前用户不存在数据库中，进行新建...");if (user_union == null) {user1 = new User();user1.setUserUnion(unionid);} else {user1 = user_union;}user1.setUserMiniWx(openid);user1.setUserMiniNick(BaseConstant.NICK_DEFAULT);user1.setUserMiniHead(BaseConstant.HEAD_DEFAULT);user1.setUserSex(1);userService.saveOrUpdate(user1);log.info("小程序用户登录,用户新建成功！user:{}", user1.toString());map.put("token", tokenService.getToken(user1));return new SuccessResponseData(map);} else {log.info("小程序用户登录，当前用户已存在数据库中，直接获取token");map.put("token", tokenService.getToken(user_mini));return new SuccessResponseData(map);}
}

/*** 获取小程序头像和昵称进行入库** @param nickName  小程序昵称* @param avatarUrl 小程序头像* @param token     token* @return 结果*/
@ResponseBody
@ApiOperation("小程序-更新头像、昵称")
@PostMapping("/updateNikeAndHead")
public ResponseData updateNikeAndHead(String nickName, String avatarUrl, String token) {log.info("小程序更新用户头像和昵称，nickName:{}，avatarUrl:{}", nickName, avatarUrl);Long userId = TokenUtil.getTokenUserIdMini(token);LambdaQueryWrapper queryWrapper = new LambdaQueryWrapper<>();queryWrapper.eq(User::getUserId, userId);User user = userService.getOne(queryWrapper);if (user != null) {user.setUserMiniNick(nickName);user.setUserMiniHead(avatarUrl);userService.updateById(user);return new SuccessResponseData();} else {log.error("小程序-更新头像跟昵称，当前token对应的用户不存在，请检查token取值");return new ErrorResponseData("用户不存在");}
}

/**** token 下发* @Title: TokenService.java* @author zhang pan* @date 2022/7/6 23:15* @version V1.0*/
@Slf4j
@Service("TokenService")
public class TokenService {public String getToken(User user) {Date start = new Date();//7天有效时间//long currentTime = System.currentTimeMillis() + 60* 60 * 1000 * 24 * 7;long currentTime = System.currentTimeMillis() + 60 * 60 * 1000 * 24;//long currentTime = System.currentTimeMillis() + 60 * 1000;Date end = new Date(currentTime);String token = "";token = JWT.create().withAudience(user.getUserId().toString()).withIssuedAt(start).withExpiresAt(end).sign(Algorithm.HMAC256("aaaaaa"));log.info("getToken..........token：{}", token);return token;}
}

注意，此处下发的token用JWT形式

4.业务扩展

1.公众号授权登录

2.开放平台unionid机制,用unionid机制，可以关联绑定在同一开放平台下的不同端用户openid，也就是openid不同，但只要帮定于同一开放平台下，则会拿到同一unionid。

/**

* 公众号登录-主入口

*

* @return 接口访问token

*/

@RequestMapping(value = "/token", method = RequestMethod.GET)

@ApiOperation("获取用户token和user信息")

public ModelAndView getToken() {

log.info("公众号用户登录获取token");

String code = request.getParameter("code");

String state = request.getParameter("state");

if (code == null) {

log.error("公众号用户登录,用户禁止未授权");

return new ModelAndView(new RedirectView(null), null);

}

// 获取到了code值，回调没有问题

// 定义地址

String token_url = BaseConstant.WX_ACCESS_TOKEN + appid +

"&secret=" + secret + "&code=" + code + "&grant_type=authorization_code";

//发送请求

ResponseEntity responseEntity = restTemplate.getForEntity(token_url, String.class);

//获取请求结果 json格式字符串

String content = responseEntity.getBody();

//把json字符串装对象

Token token = JSON.parseObject(content, Token.class);

String user_url = BaseConstant.WX_USER_INFO + token.getAccess_token() + "&openid=" + token.getOpenid();

ResponseEntity responseEntity2 = restTemplate.getForEntity(user_url, String.class);

String content1 = new String(responseEntity2.getBody().getBytes(StandardCharsets.ISO_8859_1), StandardCharsets.UTF_8);

WeiXinUser wxUser = JSON.parseObject(content1, WeiXinUser.class);

Map map = new TreeMap<>();

if (wxUser.getOpenid() == null) {

return null;

}

QueryWrapper queryWrapper = new QueryWrapper<>();

queryWrapper.eq("user_wx", wxUser.getOpenid());

User user2 = userService.getOne(queryWrapper);

//判断此用户是否存在数据库中

if (user2 == null) {

log.info("微信公众号用户登录，用户不存在数据库中，新建...");

User user1 = new User();

user1.setUserWx(wxUser.getOpenid());

user1.setUserNick(wxUser.getNickname());

user1.setUserHead(wxUser.getHeadimgurl());

user1.setUserSex(wxUser.getSex());

user1.setUserUnion(wxUser.getUnionid());

userService.save(user1);

log.info("公众号用户登录,用户新建成功！");

//构造返回

map.put("token", tokenService.getToken(user1));

map.put("user", user1.getUserPhone());

return new ModelAndView(new RedirectView(state), map);

} else {

log.info("公众号用户登录,用户存在数据库中，修改");

user2.setUserWx(wxUser.getOpenid());

user2.setUserNick(wxUser.getNickname());

user2.setUserHead(wxUser.getHeadimgurl());

user2.setUserUnion(wxUser.getUnionid());

userService.updateById(user2);

map.put("token", tokenService.getToken(user2));

map.put("user", user2.getUserPhone());

return new ModelAndView(new RedirectView(state), map);

}

}