Hibernate无法实例化抽象类或接口:java.util.List
我在实体MyUser和回路之间存在父子关系。 当我尝试使用myUserRepository.save(MyUser)保存MyUser时,出现以下错误:Hibernate无法实例化抽象类或接口:java.util.List,java,spring,hibernate,Java,Spring,Hibernate,我在实体MyUser和回路之间存在父子关系。 当我尝试使用myUserRepository.save(MyUser)保存MyUser时,出现以下错误: org.hibernate.InstantiationException: Cannot instantiate abstract class or interface: : java.util.List at org.hibernate.tuple.PojoInstantiator.instantiate(PojoInstantiat
org.hibernate.InstantiationException: Cannot instantiate abstract class or interface: : java.util.List
at org.hibernate.tuple.PojoInstantiator.instantiate(PojoInstantiator.java:79) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
at org.hibernate.tuple.component.AbstractComponentTuplizer.instantiate(AbstractComponentTuplizer.java:84) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
at org.hibernate.type.ComponentType.instantiate(ComponentType.java:580) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
at org.hibernate.type.ComponentType.deepCopy(ComponentType.java:500) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
at org.hibernate.type.ComponentType.deepCopy(ComponentType.java:497) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
at org.hibernate.type.TypeHelper.deepCopy(TypeHelper.java:54) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
以下是两个实体:
MyUser:
@Entity
@Data
public class MyUser {
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE)
private long id;
@NotBlank
private String firstName;
@NotNull
private String lastName;
@NotNull
@Email
@Column(unique = true)
private String email;
@NotBlank
private String password;
private String chargeBeeCustomerID;
private String company = null;
@Enumerated(EnumType.STRING)
private UsagePurpose usagePurpose = null;
@Enumerated(EnumType.STRING)
private CountryCode countryCode = null;
private Instant createdAt = Instant.now();
@Embedded
private MyUserDetails details = new MyUserDetails();
private double creditBalance = 0;
@OneToMany(mappedBy = "myUser", orphanRemoval = true, cascade = CascadeType.ALL, fetch = FetchType.LAZY)
private List<Circuit> circuitList = new ArrayList<>();
public void addCircuit(Circuit circuit) {
this.circuitList.add(circuit);
circuit.setMyUser(this);
}
public void removeCircuit(Circuit circuit) {
this.circuitList.remove(circuit);
circuit.setMyUser(null);
}
@Override
public String toString() {
return email;
}
}
@Entity
@Data
public class Circuit {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
@NotBlank
private String circuitID;
@NotBlank
private String name;
@NotNull
@Enumerated(EnumType.STRING)
private ContinentCode continentCode;
@Enumerated(EnumType.STRING)
private CountryCode countryCode;
@NotNull
private boolean enabled;
private boolean hasOnlyIPAclAccess;
@ElementCollection
private List<String> ipACL;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "fk_my_user")
private MyUser myUser;
public Circuit() {
circuitID = generateCircuitID();
name = circuitID;
enabled = true;
hasOnlyIPAclAccess = true;
ipACL = new ArrayList<>();
}
private static String generateCircuitID() {
return RandomStringUtils.randomAlphanumeric(15);
}
@Override
public int hashCode() {
return this.circuitID.hashCode();
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null || obj.getClass() != this.getClass())
return false;
Circuit circuit = (Circuit) obj;
return circuit.getCircuitID().equals(this.circuitID);
}
}
@实体
@资料
公共类MyUser{
@身份证
@GeneratedValue(策略=GenerationType.SEQUENCE)
私人长id;
@不空白
私有字符串名;
@NotNull
私有字符串lastName;
@NotNull
@电子邮件
@列(唯一=真)
私人字符串电子邮件;
@不空白
私有字符串密码;
私有字符串chargeBeeCustomerID;
私有字符串company=null;
@枚举(EnumType.STRING)
私人用途USAGEUSION=null;
@枚举(EnumType.STRING)
私有CountryCode CountryCode=null;
private Instant createdAt=Instant.now();
@嵌入
private MyUserDetails details=new MyUserDetails();
私人双贷方余额=0;
@OneToMany(mappedBy=“myUser”,orphanRemoving=true,cascade=CascadeType.ALL,fetch=FetchType.LAZY)
private List circuitList=new ArrayList();
公共电路(电路){
此.circuitList.add(电路);
circuit.setMyUser(本);
}
公共无效清除电路(电路){
此.circuitList.remove(电路);
circuit.setMyUser(null);
}
@凌驾
公共字符串toString(){
回复邮件;
}
}
电路:
@Entity
@Data
public class MyUser {
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE)
private long id;
@NotBlank
private String firstName;
@NotNull
private String lastName;
@NotNull
@Email
@Column(unique = true)
private String email;
@NotBlank
private String password;
private String chargeBeeCustomerID;
private String company = null;
@Enumerated(EnumType.STRING)
private UsagePurpose usagePurpose = null;
@Enumerated(EnumType.STRING)
private CountryCode countryCode = null;
private Instant createdAt = Instant.now();
@Embedded
private MyUserDetails details = new MyUserDetails();
private double creditBalance = 0;
@OneToMany(mappedBy = "myUser", orphanRemoval = true, cascade = CascadeType.ALL, fetch = FetchType.LAZY)
private List<Circuit> circuitList = new ArrayList<>();
public void addCircuit(Circuit circuit) {
this.circuitList.add(circuit);
circuit.setMyUser(this);
}
public void removeCircuit(Circuit circuit) {
this.circuitList.remove(circuit);
circuit.setMyUser(null);
}
@Override
public String toString() {
return email;
}
}
@Entity
@Data
public class Circuit {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
@NotBlank
private String circuitID;
@NotBlank
private String name;
@NotNull
@Enumerated(EnumType.STRING)
private ContinentCode continentCode;
@Enumerated(EnumType.STRING)
private CountryCode countryCode;
@NotNull
private boolean enabled;
private boolean hasOnlyIPAclAccess;
@ElementCollection
private List<String> ipACL;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "fk_my_user")
private MyUser myUser;
public Circuit() {
circuitID = generateCircuitID();
name = circuitID;
enabled = true;
hasOnlyIPAclAccess = true;
ipACL = new ArrayList<>();
}
private static String generateCircuitID() {
return RandomStringUtils.randomAlphanumeric(15);
}
@Override
public int hashCode() {
return this.circuitID.hashCode();
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null || obj.getClass() != this.getClass())
return false;
Circuit circuit = (Circuit) obj;
return circuit.getCircuitID().equals(this.circuitID);
}
}
@实体
@资料
公共级电路{
@身份证
@GeneratedValue(策略=GenerationType.IDENTITY)
私人长id;
@不空白
私有字符串电路ID;
@不空白
私有字符串名称;
@NotNull
@枚举(EnumType.STRING)
私人密码;
@枚举(EnumType.STRING)
私人国家代码国家代码;
@NotNull
启用私有布尔值;
私有布尔hasonlypaclaccess;
@元素集合
私人名单ipACL;
@manytone(fetch=FetchType.LAZY)
@JoinColumn(name=“fk\u我的用户”)
私有MyUser-MyUser;
公共电路(){
circuitID=generateCircuitID();
名称=电路ID;
启用=真;
hasOnlyIPAclAccess=true;
ipACL=新的ArrayList();
}
私有静态字符串generateCircuitID(){
返回RandomStringUtils.randomstringalphameric(15);
}
@凌驾
公共int hashCode(){
返回此.circuitID.hashCode();
}
@凌驾
公共布尔等于(对象obj){
if(this==obj)
返回true;
如果(obj==null | | obj.getClass()!=this.getClass())
返回false;
电路=(电路)obj;
返回circuit.getCircuitID().equals(this.circuitID);
}
}
值得注意的是,当我第一次创建用户时,子(回路)尚未创建。以后可能会创建很多。
这一错误背后的原因是什么?如何解决
非常感谢您的帮助。您正在尝试使用默认值启动一对多关系。不要创建新的ArrayList,而是尝试使用null启动它
这将解决您的问题,因为如果您尝试在未分配任何回路的情况下保留用户,它将起作用,否则,您将得到该错误。是的,这解决了问题。但我从这里学到了这种风格:作者使用空列表来实例化。为什么它在我的情况下不起作用?我看不到你的全部代码,但我认为这是正在发生的事情。在保留任何回路之前,您不会将其添加到用户的回路列表中。因此,由于您有一个空列表,它导致了该问题。当然,如果你有一个空值,它不会引起任何问题。