google-app-engine - Objectify 查询结果和 Datastore 查看器结果不一致的问题？

Question

我正在编写一个基于 TodoMVC angularjs ( http://todomvc.com/ ) 的示例项目，并使用带有 Google App Engine Cloud Endpoint 的后端 api，当我从 App Engine Datastore 获取待办事项列表时，我得到了一些一致性结果。

Todo 对象使用 objectify 存储在 App Engine 数据存储中。

Todo 实体编码如下:

@Entity
public class Todo {

    @Id
    private Long id;
    private String title;
    private boolean completed;
    private Date lastEdit;

    @Index
    private Long userId;

    public Todo() {
    }

    public Todo(String title, boolean completed) {
        this.title = title;
        this.completed = completed;
    }

    public Todo(Long id, String title, boolean completed) {
        this.id = id;
        this.title = title;
        this.completed = completed;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public boolean isCompleted() {
        return completed;
    }

    public void setCompleted(boolean completed) {
        this.completed = completed;
    }

    public Long getUserId() {
        return userId;
    }

    public void setUserId(Long userId) {
        this.userId = userId;
    }

    public Date getLastEdit() {
        return lastEdit;
    }

    public void setLastEdit(Date lastEdit) {
        this.lastEdit = lastEdit;
    }

    @Override
    public String toString() {
        return "Todo{" +
                "id=" + id +
                ", title='" + title + '\'' +
                ", completed=" + completed +
                ", lastEdit=" + lastEdit +
                ", userId='" + userId + '\'' +
                '}';
    }
}

在 Datastore 中保存 Todo 的操作如下:

@ApiMethod(name = "create", httpMethod =  ApiMethod.HttpMethod.POST)
public Todo create(User user, Todo todo) {
    logger.info("creating todo : " + todo.toString());

    todo.setUserId(new Long(user.getUserId()));
    todo.setLastEdit(new Date());
    ofy().save().entity(todo).now();

    return todo;
}



@ApiMethod(name = "list", httpMethod =  ApiMethod.HttpMethod.GET)
public Collection<Todo> getTodos(User user) {
    logger.info("user:" + user);

    List<Todo> todos = null;

    if (user != null) {
        todos = ofy().consistency(ReadPolicy.Consistency.STRONG).load().type(Todo.class).filter("userId", new Long(user.getUserId())).list();
    }

    logger.info("todos:" + todos);

    return todos;
}

假设我的列表中有 4 个待办事项，我将它们全部设置为已完成 (completed=true)。我在 Datastore 查看器中检查它们的状态:

然后，如果我在几秒钟后请求列表，我将遇到奇怪的一致性问题:

2014-03-08 13:08:43.326
fr.xebia.gae.todo.api.TodoEndpointV2 getTodos: todos:[
Todo{id=5639274879778816, title='vélo', completed=false, lastEdit=Fri Mar 07 23:36:08 UTC 2014, userId='104955400895435072612'}, 
Todo{id=5676830073815040, title='train', completed=true, lastEdit=Sat Mar 08 12:08:30 UTC 2014, userId='104955400895435072612'}, 
Todo{id=5717271485874176, title='avion', completed=false, lastEdit=Fri Mar 07 23:36:09 UTC 2014, userId='104955400895435072612'}, 
Todo{id=5757334940811264, title='voiture', completed=true, lastEdit=Sat Mar 08 12:08:32 UTC 2014, userId='104955400895435072612'}]

如您所见，所有待办事项的完成值并未设置为 true，它们的上次编辑日期甚至未更新

2 分钟后新请求:

2014-03-08 13:10:20.612
fr.xebia.gae.todo.api.TodoEndpointV2 getTodos: todos:[
Todo{id=5639274879778816, title='vélo', completed=false, lastEdit=Fri Mar 07 23:36:08 UTC 2014, userId='104955400895435072612'}, 
Todo{id=5676830073815040, title='train', completed=true, lastEdit=Sat Mar 08 12:08:30 UTC 2014, userId='104955400895435072612'}, 
Todo{id=5717271485874176, title='avion', completed=false, lastEdit=Fri Mar 07 23:36:09 UTC 2014, userId='104955400895435072612'}, 
Todo{id=5757334940811264, title='voiture', completed=true, lastEdit=Sat Mar 08 12:08:32 UTC 2014, userId='104955400895435072612'}]

和 17 分钟后的新请求，仍然不是好的值......

2014-03-08 13:27:07.918
fr.xebia.gae.todo.api.TodoEndpointV2 getTodos: todos:[Todo{id=5639274879778816, title='vélo', completed=false, lastEdit=Fri Mar 07 23:36:08 UTC 2014, userId='104955400895435072612'}, 
Todo{id=5676830073815040, title='train', completed=true, lastEdit=Sat Mar 08 12:08:30 UTC 2014, userId='104955400895435072612'}, 
Todo{id=5717271485874176, title='avion', completed=false, lastEdit=Fri Mar 07 23:36:09 UTC 2014, userId='104955400895435072612'}, 
Todo{id=5757334940811264, title='voiture', completed=true, lastEdit=Sat Mar 08 12:08:32 UTC 2014, userId='104955400895435072612'}]

有人知道为什么使用 Objectify 查询的内容与使用 GAE Datastore 查看器后台查看的内容之间存在如此大的差异吗？是一致性问题吗？但如果是这样，为什么数据存储查看器没有同样的问题？我在查询时是否滥用了对象化(如果我在运行过滤器时设置了 ofy().consistency(ReadPolicy.Consistency.STRONG) 事件)？

Answer 1

我没有很好地阅读 objectify 设置，我错过了告诉应该将以下内容添加到 web.xml 的部分

<filter>
     <filter-name>ObjectifyFilter</filter-name>
     <filter-class>com.googlecode.objectify.ObjectifyFilter</filter-class>
</filter>
<filter-mapping>
     <filter-name>ObjectifyFilter</filter-name>
     <url-pattern>/*</url-pattern> 
</filter-mapping>