JPA more cases than we would like

Question

I have a class called NodeTypeJPA-enabled using SQL Server database.

Nothing special, no relationship, just some fields. There are even more of them, but to simplify, I omit them:

@Entity
@Table(name="node_type")
@NamedQuery(name="NodeType.findAll", query="SELECT n FROM NodeType n")
public class NodeType implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;

    private String name;

    public NodeType() {
    }

    public int getId() {
            return this.id;
    }

    public void setId(int id) {
            this.id = id;
    }

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

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

}

When I started the application, I read them and put them in HashMap, taking the property nameas a key to make it easier to find it later.

There are currently five items in the database.

id  name       maxNoExits  mandatoryExits  defaultExits
==  =========  ==========  ==============  ============
1   NTYPE_HUP  0           NodeHangup
2   NTYPE_ANN  1           NodeAnnounce
3   NTYPE_SLP  1           NodeWait
4   NTYPE_XFR  0           NodeTransfer
5   NTYPE_TBR  32          NodeTimebased

A little later, and I don’t know exactly where this happens, several instances for each element suddenly exist (there are currently three instances per element)

Example. In the application, I have an instance of NodeType with values

1   NTYPE_HUP  0           NodeHangup

The eclipse debugger tells me that:

• , ,
• map.get null
• NodeType 15
• , .
• , . id . getHash() , equals() true, ?

, ! - , ?

JPA ( ?), , @Id. , createQuery, . ?

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Edit2: hashCode() ( return this.id;) equals() (return this.id == other.id;)

15 . , , . . , - .

Answer 1

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