问题
I am working with Spring Data Rest and Hibernate in my current project. I just added projections for some entities to reduce the amount of calls to the backend when displaying information. My code looks like this:
Component.class
@NoArgsConstructor
@RequiredArgsConstructor
@EqualsAndHashCode
@Getter
@Setter
@Slf4j
@Entity
@Table(name = "components")
public class Component
{
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "component_id", unique = true)
private Long id;
@OneToMany(fetch = FetchType.LAZY, mappedBy = "component", cascade = {
CascadeType.DETACH,
CascadeType.PERSIST,
CascadeType.REFRESH
})
private List<Parameter> parameters = new ArrayList<>();
@NonNull
@Column(name = "name", nullable = false)
private String name;
}
Parameter.class
@AllArgsConstructor
@RequiredArgsConstructor
@NoArgsConstructor
@Data
@Entity
@Table(name = "parameters")
public class Parameter
{
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "parameter_id", unique = true)
private Long id;
@NonNull
@Column(name = "name", nullable = false, unique = true)
private String key;
@ManyToOne(fetch = FetchType.EAGER)
private Component component;
@Column(name = "type")
private String type;
}
Projection class
@Projection(name = "withParameters", types = { Component.class })
public interface ComponentWithParameters
{
Long getId();
String getName();
List<Parameter> getParameters();
}
The projection should just add the parameters to the component which it does perfectly:
{
"name" : "New Component",
"id" : 1,
"parameters" : [ {
"id" : 1,
"key" : "Parameter_2",
"type" : null
}, {
"id" : 2,
"key" : "Parameter_19",
"type" : null
}, {
"id" : 18,
"key" : "Parameter_9",
"type" : null
} ],
"_links" : {
"self" : {
"href" : "https://localhost:8020/api/components/1"
},
"component" : {
"href" : "https://localhost:8020/api/components/1{?projection}",
"templated" : true
},
"parameters" : {
"href" : "https://localhost:8020/api/components/1/parameters{?projection}",
"templated" : true
}
}
}
I was expecting the parameters in the list to have all the links that Spring Data Rest normally applies. Something like this:
{
"name" : "New Component",
"id" : 1,
"parameters" : [ {
"id" : 1,
"key" : "Parameter_2",
"type" : null,
"_links":{
"self":{
"href":"http://localhost:8080/api/parameters/1{?projection}",
"templated":true
},
"component":{
"href":"http://localhost:8080/api/parameters/1/component"
}
}
}, {
"id" : 2,
"key" : "Parameter_19",
"type" : null,
"_links":{
"self":{
"href":"http://localhost:8080/api/parameters/2{?projection}",
"templated":true
},
"component":{
"href":"http://localhost:8080/api/parameters/2/component"
}
}
}, {
"id" : 18,
"key" : "Parameter_9",
"type" : null,
"_links":{
"self":{
"href":"http://localhost:8080/api/parameters/18{?projection}",
"templated":true
},
"component":{
"href":"http://localhost:8080/api/parameters/18/component"
}
}
} ],
"_links" : {
"self" : {
"href" : "https://localhost:8020/api/components/1"
},
"component" : {
"href" : "https://localhost:8020/api/components/1{?projection}",
"templated" : true
},
"parameters" : {
"href" : "https://localhost:8020/api/components/1/parameters{?projection}",
"templated" : true
}
}
}
I found this question which resembles mine a lot and it appearently was a bug and I was wondering if this is one again this time.
I am using the following versions:
- spring-data-rest-core:3.1.4.RELEASE
- spring-data-rest-webmvc:3.1.4.RELEASE
- spring-data-commons:2.1.4.RELEASE
- spring-data-jpa:2.1.4.RELEASE
Hopefully, somebody can help me figure this out. Thank you all in advance.
来源:https://stackoverflow.com/questions/54711501/missing-links-in-spring-data-rest-projection