春季开机休眠时的关系映射错误(Error in relationship mapping on spring boot hibernate)

春季开机休眠时的关系映射错误(Error in relationship mapping on spring boot hibernate)

我正在使用Spring Boot 1.5.9.RELEASE，并且在EntityManagerFactory中遇到编译时错误。 我可以在不具有任何外键的表中执行CRUD操作，但在具有外键的表中，pproject甚至不会编辑抱怨EntityManagerFactory。 我正在使用Intellij IDEA 2017.3。 以下是我的模型类：

package com.example.demo.Model; import javax.persistence.*; @Entity @Table(name = "student") public class Student { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "sid") private int id; @Column(name = "sname") private String name; @Column(name = "sroll") private int roll; @ManyToOne @JoinColumn(name = "cid", table = "college") private College college; public int getId() { return id; } public College getCollege() { return college; } public void setCollege(College college) { this.college = college; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getRoll() { return roll; } public void setRoll(int roll) { this.roll = roll; } } package com.example.demo.Model; import javax.persistence.*; import java.util.List; @Entity @Table(name = "college") public class College { @GeneratedValue(strategy = GenerationType.AUTO) @Id @Column(name = "cid") private int id; @Column(name = "cname") private String name; @OneToMany(targetEntity = Student.class, mappedBy = "college", cascade = CascadeType.ALL, fetch = FetchType.EAGER) private List<Student> studentList; public List<Student> getStudentList() { return studentList; } public void setStudentList(List<Student> studentList) { this.studentList = studentList; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } }

我的DAO类如下所示：

package com.example.demo.DAO; import com.example.demo.Model.College; import org.springframework.stereotype.Repository; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.PersistenceUnit; import javax.transaction.Transactional; @Transactional @Repository public class CollegeDAO { @PersistenceUnit EntityManagerFactory emf; public boolean add(College college) { EntityManager em = emf.createEntityManager(); em.getTransaction().begin(); em.persist(college); em.getTransaction().commit(); return true; } } package com.example.demo.DAO; import com.example.demo.Model.Student; import org.apache.tomcat.jni.Local; import org.springframework.stereotype.Repository; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.PersistenceUnit; import javax.transaction.Transactional; import java.util.List; @Transactional @Repository public class StudentDAO { @PersistenceUnit private EntityManagerFactory emf; public boolean add(Student student) { EntityManager em = emf.createEntityManager(); em.getTransaction().begin(); em.persist(student); em.getTransaction().commit(); return true; } }

错误堆栈如下所示：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: Cannot find the expected secondary table: no college available for com.example.demo.Model.Student at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1080) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at com.example.demo.DemoApplication.main(DemoApplication.java:10) [classes/:na] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_151] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_151] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_151] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_151] at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-1.5.10.RELEASE.jar:1.5.10.RELEASE] Caused by: org.hibernate.AnnotationException: Cannot find the expected secondary table: no college available for com.example.demo.Model.Student at org.hibernate.cfg.Ejb3Column.getJoin(Ejb3Column.java:452) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.cfg.Ejb3Column.getTable(Ejb3Column.java:423) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.cfg.AnnotationBinder.bindManyToOne(AnnotationBinder.java:2854) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:1763) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.cfg.AnnotationBinder.processIdPropertiesIfNotAlready(AnnotationBinder.java:911) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:738) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.processEntityHierarchies(AnnotationMetadataSourceProcessorImpl.java:245) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.processEntityHierarchies(MetadataBuildingProcess.java:222) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:265) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:847) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:874) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final] at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:360) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:382) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:371) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:336) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] ... 21 common frames omitted

I am using Spring Boot 1.5.9.RELEASE and I am facing a compile time error in EntityManagerFactory. I can do CRUD operations in tables not having any foreign keys but in tables having foreign keys, the pproject doesn't even compile complaining about EntityManagerFactory. I am using Intellij IDEA 2017.3. Below is my Model Class:

package com.example.demo.Model; import javax.persistence.*; @Entity @Table(name = "student") public class Student { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "sid") private int id; @Column(name = "sname") private String name; @Column(name = "sroll") private int roll; @ManyToOne @JoinColumn(name = "cid", table = "college") private College college; public int getId() { return id; } public College getCollege() { return college; } public void setCollege(College college) { this.college = college; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getRoll() { return roll; } public void setRoll(int roll) { this.roll = roll; } } package com.example.demo.Model; import javax.persistence.*; import java.util.List; @Entity @Table(name = "college") public class College { @GeneratedValue(strategy = GenerationType.AUTO) @Id @Column(name = "cid") private int id; @Column(name = "cname") private String name; @OneToMany(targetEntity = Student.class, mappedBy = "college", cascade = CascadeType.ALL, fetch = FetchType.EAGER) private List<Student> studentList; public List<Student> getStudentList() { return studentList; } public void setStudentList(List<Student> studentList) { this.studentList = studentList; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } }

My DAO classes are as follows:

package com.example.demo.DAO; import com.example.demo.Model.College; import org.springframework.stereotype.Repository; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.PersistenceUnit; import javax.transaction.Transactional; @Transactional @Repository public class CollegeDAO { @PersistenceUnit EntityManagerFactory emf; public boolean add(College college) { EntityManager em = emf.createEntityManager(); em.getTransaction().begin(); em.persist(college); em.getTransaction().commit(); return true; } } package com.example.demo.DAO; import com.example.demo.Model.Student; import org.apache.tomcat.jni.Local; import org.springframework.stereotype.Repository; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.PersistenceUnit; import javax.transaction.Transactional; import java.util.List; @Transactional @Repository public class StudentDAO { @PersistenceUnit private EntityManagerFactory emf; public boolean add(Student student) { EntityManager em = emf.createEntityManager(); em.getTransaction().begin(); em.persist(student); em.getTransaction().commit(); return true; } }

The error stack is as follows:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: Cannot find the expected secondary table: no college available for com.example.demo.Model.Student at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1080) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at com.example.demo.DemoApplication.main(DemoApplication.java:10) [classes/:na] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_151] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_151] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_151] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_151] at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-1.5.10.RELEASE.jar:1.5.10.RELEASE] Caused by: org.hibernate.AnnotationException: Cannot find the expected secondary table: no college available for com.example.demo.Model.Student at org.hibernate.cfg.Ejb3Column.getJoin(Ejb3Column.java:452) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.cfg.Ejb3Column.getTable(Ejb3Column.java:423) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.cfg.AnnotationBinder.bindManyToOne(AnnotationBinder.java:2854) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:1763) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.cfg.AnnotationBinder.processIdPropertiesIfNotAlready(AnnotationBinder.java:911) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:738) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.processEntityHierarchies(AnnotationMetadataSourceProcessorImpl.java:245) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.processEntityHierarchies(MetadataBuildingProcess.java:222) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:265) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:847) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:874) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final] at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:360) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:382) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:371) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:336) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] ... 21 common frames omitted

最满意答案

问题出在你的Student课上：

@ManyToOne @JoinColumn(name = "cid", table = "college") private College college;

您正试图在college表中添加cid作为列。 这没有任何意义，因为在一所大学里有更多的学生。 JoinColumn应该放在student表或辅助表中，该表将学生ID与大学ID相结合，而不是在college表中。 一种解决方法是删除table = "college"或将其更改为辅助连接表的新名称。

I am answering my own question with the suggestions given by @msparer and @bogdan-oros. This is what i did in Student model:

@ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "cid",nullable = false) private College collegeName;

and this is what i did in College Model:

@OneToMany(mappedBy = "collegeName", cascade = CascadeType.ALL, fetch = FetchType.LAZY) private Set<Student> studentSet = new HashSet<>();

I was working in Ubuntu 16.04.3, so i had to give read, write and execute permissions to .IntellijIdea2017.3 folder, the IntellijIdea folder, .m2 folder and the project folder using

sudo chmod -R 777 <folder-name>

Now everything is working as expected. Thanks guys for the help. Cheers...