GAE收藏問題

學習GAE我得到了一些問題。我想將我的用戶的聯繫人列表保存在數據庫中。我使用addUser（）來添加新用戶，它的工作原理。但是，當我刷新頁面的列表是空的（非空）。在GAE「數據存儲查看器」中，「列表」字段爲空，但在應用程序中存在。GAE收藏問題

@PersistenceCapable(identityType = IdentityType.APPLICATION, detachable="true") 
public class ContactList implements IUserList { 

    @PrimaryKey 
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) 
    private Key key; 

    @Persistent 
    protected List<Key> list; 

    @Persistent(mappedBy = "contactList") 
    private User user; 

    public Key getKey(){ 
     return this.key; 
    } 

    public User getUser() { 
     return user; 
    } 

    public ContactList(User user) { 
     this.list = new ArrayList<Key>(); //this line invoice one only 
    } 

    @Override 
    public Boolean addUser(User user) { 
     if(this.list.contains(user.getKey())){ 
      return false; 
     }else{  
      this.list.add(user.getKey()); 

      return true; 
     } 
    } 

    @Override 
    public boolean containsKey(Long id) { 
     return false; //this.list.containsKey(id); 
    } 

    @Override 
    public User get(Long id) { 
     return null;// this.list.get(id); 
    } 

    @Override 
    public void removeUser(User user) { 
     this.list.remove(user.getKey());  
    } 

    @Override 
    public int size() { 
     return this.list.size(); 
    } 

    @Override 
    public List<User> users() { 

     ArrayList<User> users = new ArrayList<User>(); 

     for(Key key : this.list) { 
      User user = UserManager.getInstance().getUser(key); 
      users.add(user); 
     }  

     return users; 
    } 

    @Override 
    public void addEvent(IEvent event) { 
     for(User user : this.users()) { 
      user.addEvent(event); 
     } 
    } 

    @Override 
    public void clearEvents() { 
    } 

    @Override 
    public ArrayList<IEvent> getEvents() { 
     return null; 
    } 



}

來源

2010-08-06 Oleh Herych