public class Management extends AbstractEnum {
    protected Management () {
    }
    public Management (final long id, final String description) {
        super(id, description);
    }
}

public abstract class AbstractEnum extends AbstractEntity {
    private String description;

    protected AbstractEnum () {
    }

    public AbstractEnum (final long id, final String description) {
        super(id);
        this.description = description;
    }

    public String getDescription () {
        return description;
    }

    public void setDescription (final String description) {
        this.description = description;
    }
}

public abstract class AbstractEntity implements Serializable {
    private long id;

    public long getId () {
        return id;
    }

    protected AbstractEntity () {
        id = 0;
    }

    public AbstractEntity (final long id) {
        this.id = id;
    }

    @Override
    public boolean equals (final Object object) {
        if (object == null || !(object instanceof AbstractEntity))
            return false;
        return id == ((AbstractEntity) object).id;
    }

    @Override
    public int hashCode () {
        return (int) id;
    }
}

    <persistence-unit-metadata>
        <xml-mapping-metadata-complete />
        <persistence-unit-defaults>
            <access>FIELD</access>
        </persistence-unit-defaults>
    </persistence-unit-metadata>

    <mapped-superclass class="my.missinglink.domain.AbstractEntity" />

    <mapped-superclass class="my.missinglink.domain.AbstractEnum">
        <attributes>
            <basic name="description">
                <column name="DESCRIPTION" />
            </basic>
        </attributes>
    </mapped-superclass>

    <entity class="my.missinglink.domain.Management">
        <table name="MANAGEMENT" />
        <attributes>
            <id name="id">
                <column name="ID_MANAGEMENT" />
            </id>
        </attributes>
    </entity>