I have to rewritew composite-id (xml) to JPA

Question

this is my xml mapping. I need to make JPA mapping

    <composite-id>
        <key-property name="systemId" type="integer" column="SYSTEM_ID"/>
        <key-property name="rollingRackId" type="integer" column="ROLLING_RACK_ID"/>
    </composite-id>

    <property name="status" type="integer" column="ROLLING_RACK_STATUS"/>
    <property name="changeTime" type="timestamp" column="CHANGE_TIME" />

</class>

Answer 1

You have to introduce an Id class

@Entity @IdClass(KeyClass.class)
public class Entity{
    @Id int systemId;
    @Id int rollingRackId;

}


class KeyClass{
    int systemId;
    int rollingRackId;
}