我是 RequestFactory 的新手,但得到了慷慨的帮助托马斯·布罗耶在查看了下面的文档之后,情况变得好多了:)
- RequestFactory 入门
- 请求工厂移动部件
- GWT 2.4 中的 RequestFactory 更改
但你能解释一下原因吗Locator<>.find()
(在我看来)经常被不必要地调用吗?
在我的示例项目中,我有两个维护父子关系的实体组织和人员。当我获取组织对象化时自动地获取子 Person。
我还在服务层创建了两个方法findOrganizationById
and saveOrganization
加载并持久化对象。
现在考虑两种情况:
当我打电话时findOrganizationById
在客户端中,以下调用发生在服务器端:
OrderDao.findOrganizationById(1)
PojoLocator.getId(Key<?>(Organization(1)))
PojoLocator.getId(Key<?>(Organization(1)/Person(2)))
PojoLocator.getId(Key<?>(Organization(1)))
PojoLocator.find(Key<?>(Organization(1)))
PojoLocator.getId(Key<?>(Organization(1)/Person(2)))
PojoLocator.find(Key<?>(Organization(1)/Person(2)))
通过致电OrderDao.findOrganizationById
我已经收到了完整的对象图。为什么打电话.find
除此之外还有两次吗?数据存储上的额外负载让我付出了金钱代价。当然,我缓存了它,但修复它会很干净。如何避免这些额外的调用?
当我通过调用保存对象时会发生类似的事情saveOrganization
在客户端中。服务器端发生以下调用:
PojoLocator.find(Key<?>(Organization(1)))
PojoLocator.find(Key<?>(Organization(1)/Person(2)))
OrderDao.saveOrganization(1)
PojoLocator.getId(Key<?>(Organization(1)))
PojoLocator.find(Key<?>(Organization(1)))
PojoLocator.getId(Key<?>(Organization(1)/Person(2)))
PojoLocator.find(Key<?>(Organization(1)/Person(2)))
我可以理解需要从 DataStore 获取两个对象before更新它。 RequestFactory 将增量发送到服务器,因此在持久化之前需要拥有整个对象。不过,由于我立即加载完整的图表,最好不要进行第二次调用,即PojoLocator.find(Key<?>(Organization(1)/Person(2)))
。我真的无法理解需要.find()
calls after坚持。
想法?
我的代理
@ProxyFor(value = Organization.class, locator = PojoLocator.class)
public interface OrganizationProxy extends EntityProxy
{
public String getName();
public void setName(String name);
public String getAddress();
public void setAddress(String address);
public PersonProxy getContactPerson();
public void setContactPerson(PersonProxy contactPerson);
public EntityProxyId<OrganizationProxy> stableId();
}
@ProxyFor(value = Person.class, locator = PojoLocator.class)
public interface PersonProxy extends EntityProxy
{
public String getName();
public void setName(String name);
public String getPhoneNumber();
public void setPhoneNumber(String phoneNumber);
public String getEmail();
public void setEmail(String email);
public OrganizationProxy getOrganization();
public void setOrganization(OrganizationProxy organization);
}
我的服务
public interface AdminRequestFactory extends RequestFactory
{
@Service(value = OrderDao.class, locator = InjectingServiceLocator.class)
public interface OrderRequestContext extends RequestContext
{
Request<Void> saveOrganization(OrganizationProxy organization);
Request<OrganizationProxy> findOrganizationById(long id);
}
OrderRequestContext contextOrder();
}
最后是我的定位器
public class PojoLocator extends Locator<DatastoreObject, String>
{
@Inject Ofy ofy;
@Override
public DatastoreObject create(Class<? extends DatastoreObject> clazz)
{
try
{
return clazz.newInstance();
} catch (InstantiationException e)
{
throw new RuntimeException(e);
} catch (IllegalAccessException e)
{
throw new RuntimeException(e);
}
}
@Override
public DatastoreObject find(Class<? extends DatastoreObject> clazz, String id)
{
Key<DatastoreObject> key = Key.create(id);
DatastoreObject load = ofy.load(key);
return load;
}
@Override
public Class<DatastoreObject> getDomainType()
{
return null; // Never called
}
@Override
public String getId(DatastoreObject domainObject)
{
Key<DatastoreObject> key = ofy.fact().getKey(domainObject);
return key.getString();
}
@Override
public Class<String> getIdType()
{
return String.class;
}
@Override
public Object getVersion(DatastoreObject domainObject)
{
return domainObject.getVersion();
}
}