实体类是非实体吗？

Question

I got the following Error:

[class model.VerkaufterArtikel] uses a non-entity [class model.Verkauf] as target entity in the relationship attribute [field verkauf].

But the class is listed in the persistence.xml. And I tried also to not exlude unlisted classes.

I'm using EclipseLink as JPA Implementation.

I tried to exlude the relation but then I was not able to persist Verkauf. The other classes are working correctly.

The situation is: I have a sale(Verkauf) wich contains sold items(VerkaufteArtikel).

model.Verkauf:

package model;


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

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

    private int verkID;



    private int gegeben;

    @OneToMany(mappedBy="verkauf")
    private List<VerkaufterArtikel> verkaufArtikels = new ArrayList<VerkaufterArtikel>();

model.VerkaufterArtikel:

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

    @Id
    private int id;

    private float anz;

    private int artID;

    private int preispro;


    @ManyToOne
    @JoinColumn(name="verkaufID")
    private Verkauf verkauf;

My persistence XML:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1"
    xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="dbm" transaction-type="RESOURCE_LOCAL">
        <!-- <exclude-unlisted-classes>false</exclude-unlisted-classes>-->
        <class>model.Artikel</class>
        <class>model.ArtikelInWarenkorb</class>
        <class>model.VerkaufterArtikel</class>
        <class>model.Verkaeufer</class>
        <class>model.Verkauf</class>
        <properties>
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/mdb" />
            <property name="javax.persistence.jdbc.user" value="user" />
            <property name="javax.persistence.jdbc.password" value="password" />
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
            <property name="eclipselink.allow-zero-id" value="true" />
        </properties>


    </persistence-unit>
</persistence>

And the Tables:

CREATE TABLE `verkauf_artikel` (
`id` INT(11) NOT NULL AUTO_INCREMENT,
`verkaufID` INT(11) NULL DEFAULT NULL,
`artID` INT(11) NULL DEFAULT NULL,
`anz` FLOAT NULL DEFAULT NULL,
`preispro` INT(11) NULL DEFAULT NULL,
PRIMARY KEY (`id`),

CREATE TABLE `verkauf` (


id` INT(11) NOT NULL AUTO_INCREMENT,
    `verkID` INT(11) NULL DEFAULT '0',
    `zeit` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `gegeben` INT(11) NOT NULL DEFAULT '0',
        PRIMARY KEY (`id`)
)
COLLATE='latin1_swedish_ci'
ENGINE=InnoDB;

Thank you!

Answer 1

I think your @ManyToOneMapping is not correct, it should look like this:

@ManyToOne
@JoinColumn(name="verkID")
private Verkauf verkauf;

Answer 2

I finally found the reason for this error.

I had a getSum() method at the bottom of the class. I removed the method and everything is working fine now!

public int getSum() {

    return (int) getVerkaufArtikels()
            .stream()
            .mapToDouble(acc -> ((double) acc.getPreispro() * acc.getAnz()))
            .sum();
}