尝试从数据库中列出带有简单约束的hibernate条件时出现错误

Criteria criteria = session.createCriteria(Licence.class);
criteria.add(Restrictions.eq("gym", gym.getId()));
List<Licence> list = criteria.list();

我有两个类：Licence与关联Gym。这两个类正在扩展DataModel，用于管理有关数据版本的信息-（创建和分配，谁和何时）。这两个类具有的重要意义@Inheritance(strategy = InheritanceType.SINGLE_TABLE)。

执照

@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
public class Licence extends DataModel implements Serializable {

    private Gym gym;
    private String licenceType;
    private String keyCode;
    private Date expireDate;
    private ELicenceExpiry expired;

    public Licence() {
    }

    @ManyToOne
    @JoinColumn(name="gym_id")
    public Gym getGym() {
        return gym;
    }

    public void setGym(Gym gym) {
        this.gym = gym;
    }

    @Column(name = "licence_type")
    public String getLicenceType() {
        return licenceType;
    }

    public void setLicenceType(String licenceType) {
        this.licenceType = licenceType;
    }

    @Column(name = "key_code")
    public String getKeyCode() {
        return keyCode;
    }

    public void setKeyCode(String keyCode) {
        this.keyCode = keyCode;
    }

    @Column(name = "expire_date")
    public Date getExpireDate() {
        return expireDate;
    }

    public void setExpireDate(Date expireDate) {
        this.expireDate = expireDate;
    }

    @Column(name = "expired")
    @Enumerated(EnumType.ORDINAL)
    public ELicenceExpiry getExpired() {
        return expired;
    }
    public void setExpired(ELicenceExpiry expired) {
        this.expired = expired;
    }
}

健身房

@Entity
@Inheritance(strategy= InheritanceType.SINGLE_TABLE)
public class Gym extends DataModel implements Serializable{

    private String shortName;
    private String name;
    private String nip; 
    private String street;
    private String postCode;
    private String localization;
    private String telephone;

    public Gym(){};

    @Column(name="short_name")
    public String getShortName() {
        return shortName;
    }
    public void setShortName(String shortName) {
        this.shortName = shortName;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getNip() {
        return nip;
    }
    public void setNip(String nip) {
        this.nip = nip;
    }
    public String getStreet() {
        return street;
    }
    public void setStreet(String street) {
        this.street = street;
    }
    @Column(name="post_code")
    public String getPostCode() {
        return postCode;
    }
    public void setPostCode(String postCode) {
        this.postCode = postCode;
    }
    public String getLocalization() {
        return localization;
    }
    public void setLocalization(String localization) {
        this.localization = localization;
    }
    public String getTelephone() {
        return telephone;
    }
    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }
}

数据模型

@MappedSuperclass
public abstract class DataModel implements Serializable{
    protected Long id;
    protected String editor;
    protected Date editDate;
    protected Time editTime;
    protected int dataState;

    @Id
    @GeneratedValue
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getEditor() {
        return editor;
    }
    public void setEditor(String editor) {
        this.editor = editor;
    }
    @Column(name="edit_date")
    public Date getEditDate() {
        return editDate;
    }
    public void setEditDate(Date editDate) {
         this.editDate = editDate;
    }
    @Column(name="edit_time")
    public Time getEditTime() {
        return editTime;
    }
    public void setEditTime(Time editTime) {
        this.editTime = editTime;
    }
    @Column(name="data_state")
    public int getDataState() {
         return dataState;
    }
    public void setDataState(int dataState) {
        this.dataState = dataState;
    }
 }

的MySQL

CREATE TABLE licence(
    id INT(5) NOT NULL AUTO_INCREMENT,
    gym_id int(3),
    licence_type VARCHAR(10),
    key_code VARCHAR(10),
    expire_date DATE,
    expired INT(1),
    editor VARCHAR(10),
    edit_date DATE,
    edit_time TIME,
    data_state INT(1) NOT NULL,
    PRIMARY KEY (id),
    FOREIGN KEY (gym_id) REFERENCES gym(id) ON DELETE SET NULL
);

CREATE TABLE gym(
    id INT(3) NOT NULL AUTO_INCREMENT,
    short_name VARCHAR(16) NOT NULL UNIQUE,
    name VARCHAR(100) NOT NULL,
    street VARCHAR(100),
    post_code VARCHAR(6),
    localization VARCHAR(64),
    nip VARCHAR(13),
    telephone VARCHAR(15),
    editor VARCHAR(10),
    edit_date DATE,
    edit_time TIME,
    data_state INT(1) NOT NULL,
    PRIMARY KEY (id)
);

例外：

org.hibernate.PropertyAccessException: IllegalArgumentException occurred calling getter of pl.fitpartner.model.DataModel.id
    at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:192)
    at org.hibernate.tuple.entity.AbstractEntityTuplizer.getIdentifier(AbstractEntityTuplizer.java:346)
    at org.hibernate.persister.entity.AbstractEntityPersister.getIdentifier(AbstractEntityPersister.java:4746)
    at org.hibernate.persister.entity.AbstractEntityPersister.isTransient(AbstractEntityPersister.java:4465)
(...)
Caused by: java.lang.IllegalArgumentException: java.lang.ClassCastException@37bd68c3
    at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:169)
    ... 28 more

我做错了什么？