代码之家 › 专栏 › 技术社区 › Patrick

Spring数据在@Scheduled和@Transactional方法中延迟加载

spring-data-jpa spring-boot hibernate java

Patrick · 技术社区 · 6 年前

@Scheduled 注释。

@Scheduled(initialDelay = 10 * 1000, fixedRate = 1000 * 1000)
public void ThemeUpdate() {
    List<ThemeIndex> indices = getServices();
    ...
}

这个 ThemeUpdate() 方法现在正在自己的线程中运行,我将丢失事务。所以我用 @Transactional

@Transactional
public List<ThemeIndex> getServices() {
    List<Service> services = serviceRepository.findServices();

    Section section = services.get(0).getSections().iterator().next();

    return null;
}

List<Service> services serviceRepository Section 这是一个 Entity 偷懒的加载为什么我会得到一个 LazyInitializationException ?

org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.example.myPorject.db.model.Service.sections, could not initialize proxy - no Session

计划时间:

@Scheduled(initialDelay = 10 * 1000, fixedRate = 10000 * 1000)
@Transactional
public void ThemeUpdate() {
    List<ThemeIndex> indices = themeUpdateServiceImpl.getIndices();
}

获取索引():

@Override
public List<ThemeIndex> getIndices() {
    return getIndices(serviceRepository
        .findServices());
}

@Override
public List<ThemeIndex> getIndices(List<Service> services) {
    return themeIndexServiceImpl.getThemeIndexes(services);
}

getThemeIndexes():

@Override
public List<ThemeIndex> getThemeIndexes(List<Service> services) {
    List<ThemeIndex> themeIndexs = new ArrayList<>();
    for (Service s : services) {
        ThemeIndex themeIndex = getThemeIndex(s);
        if (themeIndex != null) {
            themeIndexs.add(themeIndex);
        }
    }
    return themeIndexs;
}

@Override
public ThemeIndex getThemeIndex(Service service) {
    //SQL which is slow
    if (serviceRepository.isEpisService(service.getSvno())) {
        ...
    }