Question

我的目标是使用带有JPA注释的Hibernate OGM（4.1.1 Final）在MongoDB商店中保存一棵树。我写了两个名为Node和NodeLink的类：第一个定义节点，第二个定义节点之间的链接。

Node类：

@Entity
public class Node {

private Set<NodeLink> children;

private String id;
private String name;

public Node() {
    children = new HashSet<>();
}

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Type(type = "objectid")
public String getId() {
    return id;
}
public void setId(String id) {
    this.id = id;
}

public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}

@OneToMany( mappedBy="source" )
public Set<NodeLink> getChildren() {
    return children;
}
void setChildren(Set<NodeLink> children) {
    this.children = children;
}

}

NodeLink类：

@Entity
public class NodeLink {

private String id;

private Node source;
private Node target;

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Type(type = "objectid")
public String getId() {
    return id;
}
public void setId(String id) {
    this.id = id;
}

@ManyToOne
public Node getSource() {
    return source;
}
void setSource(Node source) {
    this.source = source;
}
public void assignSource(Node source) {
    setSource(source);
    source.getChildren().add(this);
}

@ManyToOne
public Node getTarget() {
    return target;
}
void setTarget(Node target) {
    this.target = target;
}
public void assignTarget(Node target) {
    setTarget(target);
}

}

创建类并保留它们的代码如下：

    EntityTransaction transaction1 = manager.getTransaction();
    transaction1.begin();

    Node root = new Node();
    root.setName("root");
    Node children1 = new Node();
    children1.setName("children1");
    Node children2 = new Node();
    children2.setName("children2");

    NodeLink nl1 = new NodeLink();
    nl1.assignSource(root);
    nl1.assignTarget(children1);

    NodeLink nl2 = new NodeLink();
    nl2.assignSource(root);
    nl2.assignTarget(children2);

    manager.persist(root);
    manager.persist(children1);
    manager.persist(children2);
    manager.persist(nl1);
    manager.persist(nl2);

    transaction1.commit();

What is persisted in MongoDB is this.

从图像中可以看出，'root'节点是正确持久的，并且正确引用了子节点。相反，'children1'和'children2'节点每个都有一个NodeLink对象的引用，即使原始对象没有它们。所以我的问题是：这种行为是由于Hibernate OGM或MongoDB中的一个错误造成的？否则我的代码中有错误？

Answer 1

我认为你发现了一个错误。我创建了一个问题并发送了拉取请求：https://hibernate.atlassian.net/browse/OGM-1198

您可以尝试测试拉取请求或等到下一个版本。感谢

使用Hibernate OGM和MongoDB保留树，表示树的集合不正确

1 个答案: