Question

我在MongoDB中使用Hibernate OGM（5.0.3.Final）。我已将此复合Structure与策略= InheritanceType.SINGLE_TABLE一起保留。当我尝试查询TextNode时，我找到了属性＆＃34; text＆＃34; null，但如果我用mongo shell检查数据库，我可以看到属性文本不为null。 Here the DB。我报告下面使用的代码。

节点类：

@Entity
@Inheritance( strategy=InheritanceType.SINGLE_TABLE )

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

public String getName() {
    return 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);
}

}

SimpleNode类：

@Entity
public class SimpleNode extends Node {

public SimpleNode() {
    super();
}
}

TextNode类：

@Entity
public class TextNode extends Node {

private String text;

public TextNode() {
    super();
}

public String getText() {
    return text;
}
public void setText(String text) {
    this.text = text;
}

}

主要课程：

public class MainNode {
private static EntityManagerFactory ENTITY_MANAGER_FACTORY;
private static EntityManager manager;

public static void main(String[] args) {
    ENTITY_MANAGER_FACTORY = Persistence.createEntityManagerFactory("JavaHelps");
    manager = ENTITY_MANAGER_FACTORY.createEntityManager();

    createDB();
    queryDB();
}

//
// CREATE DB
//

private static void createDB() {
    EntityTransaction transaction1 = manager.getTransaction();
    transaction1.begin();

    Node root1 = new SimpleNode();
    root1.setName("root");
    Node child1 = new SimpleNode();
    child1.setName("children1");
    TextNode child2 = new TextNode();
    child2.setName("children2");
    child2.setText("a text");

    NodeLink nl4=new NodeLink();
    nl4.assignSource(root1);
    nl4.assignTarget(child1);

    NodeLink nl3=new NodeLink();
    nl3.assignSource(root1);
    nl3.assignTarget(child2);

    manager.persist(root1);
    manager.persist(child1);
    manager.persist(child2);
    manager.persist(nl4);
    manager.persist(nl3);

    transaction1.commit();
}


//
// QUERY DB
//

@SuppressWarnings("unchecked")
private static void queryDB() {
"db.Node.find({'type_id':"+"ObjectId('"+typeId+"')})";
    Node node = manager.find(SimpleNode.class,    "5832c8762fc11706a29125b5");
    print(node);
}

private static void print(Node n) {
    System.out.println(n.getClass().getSimpleName() + " : " + n.getName() + " : " + (n.getClass().getSimpleName().equals("TextNode")? ((TextNode)n).getText() : "") );
    for(NodeLink c : n.getChildren()) {
        print(c.getTarget());
    }
}

}

我的问题是：我在Hibernate OGM中发现错误或我的代码中有错误？感谢。

Hibernate OGM和MongoDB，查询复合结构的结果是不正确的

0 个答案: