我有两个外键关系表。我试过搜索如何做到这一点,它总是导致OneToMany和ManyToOne映射。我有这两张桌子。
USER_ROLE
用户
我正在尝试显示所有用户并通过将position列的值获取到user_role表来显示其位置。
这些是我的课程
user.Java
@Entity
@Table(name="user")
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
..........
private UserRole userRole;
@ManyToOne()
@JoinColumn(name="role_id")
public UserRole getUserRole() {
return userRole;
}
public void setUserRole(UserRole userRole) {
this.userRole = userRole;
}
.......
}
user role.Java
@Entity
@Table(name="user_role")
public class UserRole {
.......
private List<User> user;
@OneToMany(targetEntity=User.class, mappedBy="userRole",cascade=CascadeType.ALL, fetch = FetchType.LAZY)
public List<User> getUser() {
return user;
}
public void setUser(List<User> user) {
this.user = user;
}
public long getRole_id() {
return role_id;
}
public void setRole_id(long role_id) {
this.role_id = role_id;
}
.........
}
而且我一直收到这个错误。
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not determine type for: java.util.List, at table: user_role, for columns: [org.hibernate.mapping.Column(user)]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1699) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:573) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1089) ~[spring-context-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:859) ~[spring-context-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:780) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:412) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:333) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1277) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1265) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at com.rtc_insurance.AdminApplication.main(AdminApplication.java:10) [classes/:na]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not determine type for: java.util.List, at table: user_role, for columns: [org.hibernate.mapping.Column(user)]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:402) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:377) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1758) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1695) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
... 16 common frames omitted
Caused by: org.hibernate.MappingException: Could not determine type for: java.util.List, at table: user_role, for columns: [org.hibernate.mapping.Column(user)]
at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:456) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:423) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.mapping.Property.isValid(Property.java:226) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:597) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.mapping.RootClass.validate(RootClass.java:265) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.boot.internal.MetadataImpl.validate(MetadataImpl.java:329) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:461) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:892) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:57) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:390) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
... 20 common frames omitted
这是我第一次使用弹簧,所以我不熟悉。任何帮助将不胜感激。
您可以将关系移动到这样的相关对象
@ManyToOne()
@JoinColumn(name="role_id", referencedColumnName = "role_id", insertable = false, updatable = false)
private UserRole userRole;
和userRole一样
@OneToMany(targetEntity=User.class, mappedBy="userRole",cascade=CascadeType.ALL, fetch = FetchType.LAZY)
private List<User> user = new ArrayList<>();
更新
jar文件似乎已损坏。尝试从.m2 \ repository和mvn clean install
中删除内容
要么
右键单击您的项目,选择Maven,更新项目,选中强制更新快照/版本。
我可以通过混合字段和属性之间的注释映射来重新创建异常。我在上面描述的问题中看到你注释了字段Id,但是然后注释属性userRole,如果我这样做我得到相同的错误。我可以通过仅注释属性或字段来修复错误。这两种模型都有效:
@Entity
@Table(name = "USER")
public class User {
private Long id;
private UserRole userRole;
String userName;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
@Column(name = "USER_NAME")
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
@ManyToOne()
@JoinColumn(name="role_id")
public UserRole getUserRole() {
return userRole;
}
public void setUserRole(UserRole userRole) {
this.userRole = userRole;
}
}
这也有效:
@Entity
@Table(name = "USER")
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@ManyToOne()
@JoinColumn(name="role_id")
private UserRole userRole;
@Column(name = "USER_NAME")
String userName;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public UserRole getUserRole() {
return userRole;
}
public void setUserRole(UserRole userRole) {
this.userRole = userRole;
}
}
注释字段的其他模型对象的示例
@Entity
@Table(name = "USER")
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@ManyToOne()
@JoinColumn(name="role_id")
private UserRole userRole;
@Column(name = "USER_NAME")
String userName;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public UserRole getUserRole() {
return userRole;
}
public void setUserRole(UserRole userRole) {
this.userRole = userRole;
}
}
测试代码(我添加了这个,因为经常会混淆,必须设置双向关系才能让用户和userRole一直保存到UserRole)。
List<User> users = new ArrayList<>();
User user1 = new User();
user1.setUserName("user1");
users.add(user1);
User user2 = new User();
user2.setUserName("user2");
users.add(user2);
UserRole userRole = new UserRole();
userRole.setRoleName("admin");
//Unidirectional relationship
user1.setUserRole(userRole);
user2.setUserRole(userRole);
//set Bidirectional relationship
userRole.setUsers(users);
userRole = userRoleRepository.save(userRole);
//Show that the two users and the UserRole persisted
UserRole result = userRoleRepository.findById(userRole.getId()).get();
assertEquals(2, result.getUsers().size());
您必须注释Java字段而不是getter,如:
@OneToMany(targetEntity=User.class, mappedBy="userRole",cascade=CascadeType.ALL, fetch = FetchType.LAZY)
private List<User> user;
并为User.class
@ManyToOne
@JoinColumn(name="role_id")
private UserRole userRole;
另外,你在role_id
表中定义了user
列吗?我在屏幕截图中看不到这一点
只需提示,检查您的实体类,并确保在类声明语句之前包含@Entity注释。
@Entity
public class MyEntityClass{
//code
}
然后在@ManyToMany或@OneToMany关系下使用上述MyEntityClass的任何其他实体类中添加以下内容。
@OneToMany(mappedBy="mappingItem", cascade=CascadeType.ALL, orphanRemoval=true)
@JsonIgnore
private List<MyEntityClass> myEntityClassItemList;
这种方法对我有用,可能会有所帮助。