<dependency>  <groupId>org.springframework.boot</groupId>  <artifactId>spring-boot-starter-data-mongodb</artifactId></dependency>

spring.data.mongodb.host=spring.data.mongodb.port=spring.data.mongodb.database=xiaojuSurvey

import com.xiaojusurvey.engine.repository.MongoRepository;
@Service("authService")public class AuthServiceImpl implements AuthService {
    @Resource    private MongoRepository mongoRepository;    	@Override    public CaptchaVo captcha() {        Captcha captcha = captchaGenerator.generateRandomText(4);        mongoRepository.save(captcha);        return captchaGenerator.generateRandomSvg(captcha);    }}

XIAOJU_SURVEY_MONGO_DB_NAME=xiaojuSurveyXIAOJU_SURVEY_MONGO_URL=mongodb://localhost:27017XIAOJU_SURVEY_MONGO_AUTH_SOURCE=admin