Android 在greenDAO中有一个查询忽略会话缓存

我目前跟踪应用程序中某些对象的个别更改。通过将当前对象（用户修改过的副本）与数据库中的对象进行比较，这已经很好地工作了

public void syncChanges(GsonTask current, GsonTask old) {
    // Load previous version of object if not provided.
    if (old == null) {
        // Here I get the old object from the database, while the user modified one is not touched.
        old = TasksService.getInstance().loadTask(current.getId());
    }

    // Bunch of logic to compare the current and old objects and track changes...

    // Another bunch of logic to sync the changes found to the server.

    // Save the current state of the object to the database (replacing the old one).
    TasksService.getInstance().saveTask(current);
}

但是这种方法会带来性能问题，因为我需要复制从greenDAO获得的对象，以便以后能够比较它们。因此，本质上，我并没有利用会话缓存，因为新对象（副本）总是在查询之后创建的

public List<GsonTask> loadAllTasks() {
    // Load data from greenDAO and create the user modifiable copies.
    return gsonFromTasks(mExtTaskDao.listAllTasks());
}

private List<GsonTask> gsonFromTasks(List<Task> tasks) {
    List<GsonTask> gsonTasks = new ArrayList<GsonTask>();
    if (tasks != null) {
        // Create the copies.
        for (Task task : tasks) {
            gsonTasks.add(new GsonTask(...));
        }
    }
    return gsonTasks;
}

---

当我从数据库中查询对象以与其用户修改的状态进行比较时，我希望能够接收一个新对象，而不是对以前加载的对象的引用。这有可能吗？

显然我不允许在这里重复我的答案，但请参阅stackoverflow.com/a/47401143/2775083上关于为什么会发生这种行为的我的答案

public List<Task> loadAllTasks() {
    List<Task> tasks = mExtTaskDao.listAllTasks();

    // Return the greenDAO objects directly, without creating copies.
    return tasks != null ? tasks : new ArrayList<Task>();
}

public void syncChanges(GsonTask current, GsonTask old) {
    if (old == null) {
         // Here I can no longer load the previous state of this object (i.e. what's actually persisted in the database).
         // old is now just a reference to current.
         old = TasksService.getInstance().loadTask(current.getId());
    }

    // Comparison between the user modified object and what's in the database can't happen, as both objects are the same. 

    // I get sad. :/ Syncing changes is no longer possible.

    // Saving the current state of the object still works, as expected.
    TasksService.getInstance().saveTask(current);
}

public Task selectTask(Long id) {
    // Here I'd like to receive a new object, not the existing reference.
    return mDao.queryBuilder().where(TaskDao.Properties.Id.eq(id)).unique();
}