在对使用ObjectBox数据库的类进行单元测试时,我遇到了这个错误:
io.objectbox.exception.DbDetachedException:无法解析分离实体的关系
我已将所有必要的数据实施到我的Entity类中,以便在macOs上进行单元测试。因此,实体关系具有指向自身的一对一和多对多关系。
@Entity
data class Category(
@Id var id: Long? = 0,
var title: String?,
@JvmField var parent: ToOne<Category>? = null,
@JvmField @Backlink(to = "parent") var subCategories: ToMany<Category>? = null){
constructor(): this(id = 0, title = "", parent = null, subCategories = null)
constructor(title: String): this(id = 0, title = title, parent = null, subCategories = null)
// normally transformer would add field, but need to manually for local unit tests
@JvmField @Transient var __boxStore: BoxStore? = null
init{
if(parent == null) parent = ToOne(this, Category_.parent)
if(subCategories == null) subCategories = ToMany(this, Category_.subCategories)
}
}
单元测试非常简单:
public class CategoryModelDataMapperTest {
private CategoryModelDataMapper categoryModelDataMapper = new CategoryModelDataMapper();
@Before
public void setUp() throws Exception {
categoryModelDataMapper = new CategoryModelDataMapper();
}
@Test
public void testShouldTransformDomainModelWithoutParentToEntityCorrectly() throws Exception{
final Category category = new Category(10L, "Bar", null, null);
final CategoryModel categoryModel = categoryModelDataMapper.transform(category);
assertEquals((Long) 10L, categoryModel.getId());
assertEquals("Bar", categoryModel.getTitle());
assertNull(categoryModel.getParent());
assertNotNull(categoryModel.getSubCategories());
assertTrue(categoryModel.getSubCategories().isEmpty());
}
}
我正在测试的实际课程是普通的映射器:
class CategoryModelDataMapper: BaseMapper<Category, CategoryModel>{
override fun transform(from: Category): CategoryModel {
val toModel = CategoryModel()
toModel.id = from.id
toModel.title = from.title
toModel.parent = from.parent?.target?.let { transform(it) }
from.subCategories?.let {
it.forEach{ toModel.subCategories?.add( transform(it)) }
}
return toModel
}
override fun transform(fromList: MutableList<Category>): MutableList<CategoryModel> {
val toList = ArrayList<CategoryModel>(fromList.size)
return fromList.mapTo(toList) { transform(it) }
}
}
我有一些其他测试更详细地测试parent
和subCategories
,但我在所有测试中都遇到了同样的错误。
在它工作正常之前,但是出了点问题。
答案 0 :(得分:1)
你有完整的堆栈跟踪吗?否则很难确定问题。
我假设异常来自某处(?):
from.subCategories?.let {
it.forEach{ toModel.subCategories?.add( transform(it)) }
}
该CategoryModel也是@Id(assignable=true)
的实体?
toModel.id = from.id
在这种情况下,请务必在修改box.attach(toModel)
:
ToMany
CategoryModel toModel = CategoryModel()
toModel.id = from.id
box.attach(toModel) // need to attach box first
toModel.subCategories.add(...)
来源:见Updating ToMany section in the ObjectBox Relations documentation。