Question

Objectify文档（https://github.com/objectify/objectify/wiki/Entities）对我来说非常浅薄，只给出了一个在数据存储区中保存实体的示例。

我希望使用android studio在我的开发GAE服务器中保存一个名为 Presidents 的组下的5个实体。根据我对文档的理解，我应该这样做

@Entity
public class Presidents{
 @Id Long id;
String name;
int age;

public Presidents(Long pId, String pName, int pAge){
 id = pId;
 name = pName
 age = pAge;
}
}

然后我注册我的课程并像这样使用它（我使用junit来执行测试）

public PresidentsOfKenyaTest{

 static{
 ObjectifyService.register(Presidents.class);
 }

  private final LocalServiceTestHelper helper =
  new LocalServiceTestHelper(new LocalDatastoreServiceTestConfig());


@Before
public void setUp() {
    helper.setUp();
}
@Test
Public void nameOfPresidents(){
Presidents p1 = new Presidents(new Long(1),Daniel,88);
Presidents p2 = new Presidents(new Long(2),Mwai,81);
Presidents p3 = new Presidents(new Long(3),Daniel,70);

 ofy().save().entities.(p1,p2,p3).now();
}

@After
public void tearDown() {
    helper.tearDown();
}
}

然而，当我在android studio中运行上述类的Junit测试时，我得到了下面的例外

 java.util.ServiceConfigurationError:com.google.appengine
 .tools.development.LocalRpcService: Provider com.google.appengine.api.
datastore.dev.LocalCloudDatastoreV1Service could not be instantiated


at PresidentsOfKenyaTest.tearDown(PresidentsOfKenyaTest.java:40)

Caused by: java.lang.NoClassDefFoundError: Could not initialize class com.google.appengine.api.datastore.dev.LocalCloudDatastoreV1Service
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at java.lang.Class.newInstance(Class.java:442)
at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:380)
... 40 more

问题

我能以正确的方式保存我的实体吗？
导致上述异常的原因是什么？我应该如何解决？

如何在数据存储区中使用objectify创建实体组并保存实体

0 个答案: