[英]Spring Data REST MongoDB: Retrieve objects of DBRef instead of href
Hello experts @ stackOverflow, 你好专家@ stackOverflow,
We are using Spring Data REST MongoDB. 我们正在使用Spring Data REST MongoDB。
Is it possible to eager load the child Objects, instead of Hyperlinks - which are annotated using @DBRef? 是否有可能急于加载子对象,而不是使用@DBRef注释的超链接? Please refer the
Process.templates
attribute below. 请参阅下面的
Process.templates
属性。
Here is our Model: 这是我们的模型:
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.DBRef;
import org.springframework.data.mongodb.core.mapping.Document;
import java.util.ArrayList;
import java.util.List;
@Document(collection = "process")
public class Process {
@Id
private String id;
private String name;
@DBRef ///////// ------> This is the corresponding attribute <------
private List<MergeTemplate> templates = new ArrayList<>();
Here is our Repository: 这是我们的存储库:
import org.springframework.data.mongodb.repository.MongoRepository;
import org.springframework.data.rest.core.annotation.RepositoryRestResource;
@RepositoryRestResource(collectionResourceRel = "process", path = "process")
public interface ProcessRepository extends MongoRepository<Process, String> {
}
FindAll API brings links to the child objects FindAll API带来了子对象的链接
http://localhost:8080/data/process
Brings the following JSON. 带来以下JSON。
{
"_embedded" : {
"process" : [ {
"id" : "56d731b82b45ee21a0d2ab0a",
"name" : "application-kit",
"_links" : {
...,
/********** This is the attribute in question (templates) ************/
"templates" : {
"href" : "http://localhost:8080/data/process/56d731b82b45ee21a0d2ab0a/templates"
}
}
}, ...]
}
I even tried @DBRef(lazy=false)
, but there is no luck. 我甚至试过
@DBRef(lazy=false)
,但没有运气。
Thanks in advance! 提前致谢!
You have two possibilities: 你有两种可能性:
MergeResult
s in the Process
documents (I don't know if it is applicable for your case, but it would be the best choice even if you have a lot of MergeResult
s since @DBRef
is something like a SQL join, and MongoDB isn't great at that) MergeResult
存储在Process
文档中(我不知道它是否适用于您的情况,但即使您有很多MergeResult
,它也是最佳选择,因为@DBRef
类似于SQL连接和MongoDB)那不是很好) Using an Excerpt 使用摘录
You can achieve your goal with the following steps: 您可以通过以下步骤实现目标:
1) Create a projection of your Process document 1)创建Process文档的投影
@Projection(name = "inlineTemplates", types = { Process.class })
interface InlineTemplates {
String getId();
String getName();
// using getTemplates() inside a projection causes the information to be inlined
List<MergeTemplate> getTemplates();
}
2) Edit your repository 2)编辑您的存储库
@RepositoryRestResource(excerptProjection = InlineTemplates.class)
interface ProcessRepository extends CrudRepository<Process, String> {}
3) Go to http://localhost:8080/data/process
to see the result 3)转到
http://localhost:8080/data/process
查看结果
NOTE: I didn't try the code, just take the instructions from the documentation. 注意:我没有尝试代码,只需要从文档中获取说明。 Sorry if it doesn't work.
对不起,如果它不起作用。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.