将扩展 jhipster 用户的 UserExtra 设置为与另一个实体的关系答案

【问题标题】：Setting an UserExtra, which extends the jhipster User, into relationship to another entity将扩展 jhipster 用户的 UserExtra 设置为与另一个实体的关系
【发布时间】：2018-07-06 15:10:37
【问题描述】：

根据 Spring Data JPA Property Expressions 在 jhipster (4.14.4) 中我的 UserExtraRepository.java 中的查询

UserExtra findOneByUserLogin(String login)

应该返回一个 UserExtra-Object，它与用户 (jhi_user) 具有 1:1 的关系，其中用户由其login 字符串识别。

但是当我尝试在另一个实体资源类 (PartyFoodResource.java) 的 POST 方法中使用它时，我得到一个空指针异常：

// set UserExtra from logged in User (jhi_user) as Owner of PartyFood-Object
    String userLogin = SecurityUtils.getCurrentUserLogin().get();
    if(userLogin == ""){
        throw new IllegalArgumentException("userLogin can not be empty!");
    }
    log.debug("userLogin is '" + userLogin + "'");
    UserExtra userExtra = new UserExtra();
    userExtra = userExtraService.findOneByUserLogin(userLogin);
    log.debug("userExtra gefunden : {}", userExtra);
    partyFood.setUserExtra(userExtra);

    PartyFood result = partyFoodService.save(partyFood);

你能给我一个提示吗，我现在不明白什么？

编辑：如果我尝试the answer from agilob，我也会得到一个空指针异常，final Optional<User> isUser = userService.getUserWithAuthorities();

如果我尝试

    String loggedInUser = SecurityUtils.getCurrentUserLogin().get();
    log.debug("user gefunden : {}", loggedInUser);

    final Optional<User> isUser = userService.getUserWithAuthoritiesByLogin(loggedInUser);

我得到一个带有登录字符串的调试日志条目，但仍然是带有userService.getUserWithAuthoritiesByLogin(loggedInUser); 的空指针异常

【问题讨论】：

标签： java spring-data-jpa jhipster

【解决方案1】：

我已删除 PartyFoodResource.java 中的代码并将其粘贴到 PartyFoodServiceImpl.java 中。它现在正在与：

/**
 * Save a partyFood.
 *
 * @param partyFood the entity to save
 * @return the persisted entity
 */
@Override
public PartyFood save(PartyFood partyFood) {
    log.debug("Request to save PartyFood : {}", partyFood);

 /**
 * Add the logged in user into a relation to newly created records of the entity PartyFood.
 * The user will be the owner of the PartyFood.
 */

    final Optional<User> isUser = userService.getUserWithAuthorities();
    if (!isUser.isPresent()) {
        log.debug("User is not logged in");
    }

    final User user = isUser.get();

    UserExtra userExtra = new UserExtra();
    userExtra = userExtraService.findOneByUserId(user.getId());
    log.debug("userExtra gefunden : {}", userExtra.getUser().getLogin());
    partyFood.setUserExtra(userExtra);

    PartyFood result = partyFoodRepository.save(partyFood);
    partyFoodSearchRepository.save(result);
    return result;
}

【讨论】：