为什么Google Appengine API数据存储区实体没有空的构造函数？
[英]Why does the google appengine api datastore Entity not have an empty constructor?
问题描述
When I pass an entity from ios to a backendAPI method that expects an entity I get the error "... No suitable constructor found for type [simple type, class com.google.appengine.api.datastore.Entity] ..." Why does the google appengine api datastore Entity not have an empty constructor? 
当我将实体从ios传递到需要实体的backendAPI方法时，出现错误“ ...没有找到类型[简单类型，类com.google.appengine.api.datastore.Entity]的合适的构造函数...”为什么Google Appengine API数据存储区实体没有空的构造函数？ Also, is there a way for me to provide a suitable constructor other than using objectify? 另外，除了使用objectify之外，是否有其他方法可以提供合适的构造函数？ I tried using objectify and was able to get rid of the error but then the values of all my properties were deleted and set to null. 我尝试使用objectify并能够摆脱该错误，但是随后删除了我所有属性的值并将其设置为null。
1 个解决方案
解决方案1
0 2015-04-16 14:52:30
(I'm assuming you're using Java language) （我假设您正在使用Java语言）
There is no empty-constructor because to create an Entity you need to specify a Key or a Kind-Id/Name 没有空构造函数，因为要创建Entity您需要指定Key或Kind-Id/Name
Source: https://cloud.google.com/appengine/docs/java/javadoc/com/google/appengine/api/datastore/Entity 来源： https ： //cloud.google.com/appengine/docs/java/javadoc/com/google/appengine/api/datastore/Entity
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