添加 @OneToOne 注释时在 Spring 中启动 ApplicationContext 时出错答案

【问题标题】：Error starting ApplicationContext in Spring when add @OneToOne Annotation添加 @OneToOne 注释时在 Spring 中启动 ApplicationContext 时出错
【发布时间】：2020-09-11 02:02:34
【问题描述】：

：我是 Java Spring MVC 的初学者，我想使用 spring boots 创建一个简单的程序。但我有一个问题：当我将@OneToOne 和@JoinColumn 添加到我的模型类时，项目没有启动！错误：

启动 ApplicationContext 时出错。显示条件报告在启用“调试”的情况下重新运行您的应用程序。 2020-05-24 15:24:45.140 错误 5368 --- [主] os.boot.SpringApplication
: 应用程序运行失败

org.springframework.beans.factory.UnsatisfiedDependencyException：创建文件中定义的名称为“homeController”的 bean 时出错 [C:\Users\HamidS\Desktop\application\target\classes\crud\example\application\Controller\HomeController.class]：通过构造函数参数 0 表示的不满足的依赖关系；嵌套异常是 org.springframework.beans.factory.UnsatisfiedDependencyException：创建文件中定义的名称为“bookServices”的 bean 时出错 [C:\Users\HamidS\Desktop\application\target\classes\crud\example\application\Services\Service\BookServices.class]：通过构造函数参数 0 表示的不满足的依赖关系；嵌套异常是 org.springframework.beans.factory.BeanCreationException：错误创建在类路径中定义的名称为“sessionFactory”的bean 资源 [crud/example/application/config.class]：Bean 实例化通过工厂方法失败；嵌套异常是 org.springframework.beans.BeanInstantiationException：失败实例化[org.hibernate.SessionFactory]：工厂方法 'sessionFactory' 抛出异常；嵌套异常是 org.hibernate.AnnotationException: @OneToOne 或 @ManyToOne on crud.example.application.Models.Book.lessons 引用了一个未知数实体：crud.example.application.Models.lesson at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:798) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:228) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1358) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1204) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:895) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 crud.example.application.Application.main(Application.java:10) ~[classes/:na] 原因： org.springframework.beans.factory.UnsatisfiedDependencyException：创建文件中定义的名称为“bookServices”的 bean 时出错 [C:\Users\HamidS\Desktop\application\target\classes\crud\example\application\Services\Service\BookServices.class]：通过构造函数参数 0 表示的不满足的依赖关系；嵌套异常是 org.springframework.beans.factory.BeanCreationException：错误创建在类路径中定义的名称为“sessionFactory”的bean 资源 [crud/example/application/config.class]：Bean 实例化通过工厂方法失败；嵌套异常是 org.springframework.beans.BeanInstantiationException：失败实例化[org.hibernate.SessionFactory]：工厂方法 'sessionFactory' 抛出异常；嵌套异常是 org.hibernate.AnnotationException: @OneToOne 或 @ManyToOne on crud.example.application.Models.Book.lessons 引用了一个未知数实体：crud.example.application.Models.lesson at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:798) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:228) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1358) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1204) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1306) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1226) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:885) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:789) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] ... 20个常用框架省略原因： org.springframework.beans.factory.BeanCreationException：错误创建在类路径中定义的名称为“sessionFactory”的bean 资源 [crud/example/application/config.class]：Bean 实例化通过工厂方法失败；嵌套异常是 org.springframework.beans.BeanInstantiationException：失败实例化[org.hibernate.SessionFactory]：工厂方法 'sessionFactory' 抛出异常；嵌套异常是 org.hibernate.AnnotationException: @OneToOne 或 @ManyToOne on crud.example.application.Models.Book.lessons 引用了一个未知数实体：crud.example.application.Models.lesson at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:656) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:484) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1306) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1226) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:885) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:789) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] ... 34个常用框架省略原因： org.springframework.beans.BeanInstantiationException：失败实例化[org.hibernate.SessionFactory]：工厂方法 'sessionFactory' 抛出异常；嵌套异常是 org.hibernate.AnnotationException: @OneToOne 或 @ManyToOne on crud.example.application.Models.Book.lessons 引用了一个未知数实体：crud.example.application.Models.lesson at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:651) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] ... 48个常用框架省略引起：org.hibernate.AnnotationException：@OneToOne 或 crud.example.application.Models.Book.lessons 上的@ManyToOne 参考资料一个未知的实体：crud.example.application.Models.lesson at org.hibernate.cfg.ToOneFkSecondPass.doSecondPass(ToOneFkSecondPass.java:97) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final] 在 org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processEndOfQueue(InFlightMetadataCollectorImpl.java:1786) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final] 在 org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processFkSecondPassesInOrder(InFlightMetadataCollectorImpl.java:1730) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final] 在 org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1617) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final] 在 org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:278) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final] 在 org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final] 在 org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:418) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final] 在 org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final] 在 org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:692) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final] 在 org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:727) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final] 在 crud.example.application.config.sessionFactory(config.java:18) 〜[类/：na]在 crud.example.application.config$$EnhancerBySpringCGLIB$$2bb57076.CGLIB$sessionFactory$0() 〜[类/：na]在 crud.example.application.config$$EnhancerBySpringCGLIB$$2bb57076$$FastClassBySpringCGLIB$$ce3a25e0.invoke() 〜[类/：na]在 org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 crud.example.application.config$$EnhancerBySpringCGLIB$$2bb57076.sessionFactory() 〜[类/：na]在 java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native 方法）~[na:na] 在 java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] 在 java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] 在 java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] 在 org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] ... 49个常用框架省略

2020-05-24 15:24:45.140 警告 5368 --- [主要] os.boot.SpringApplication：无法关闭应用上下文

org.springframework.beans.factory.UnsatisfiedDependencyException：创建名为“springApplicationAdminRegistrar”的 bean 时出错在类路径资源中定义 [org/springframework/boot/autoconfigure/admin/SpringApplicationAdminJmxAutoConfiguration.class]：通过方法表达的不满足的依赖关系 'springApplicationAdminRegistrar'参数1；嵌套异常是 org.springframework.beans.factory.NoSuchBeanDefinitionException: 否 'org.springframework.core.env.Environment' 类型的限定 bean 可用：预计至少有 1 个符合 autowire 条件的 bean 候选人。依赖注解：{} at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:798) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:539) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:207) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.context.event.AbstractApplicationEventMulticaster.retrieveApplicationListeners(AbstractApplicationEventMulticaster.java:245) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.context.event.AbstractApplicationEventMulticaster.getApplicationListeners(AbstractApplicationEventMulticaster.java:197) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:134) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:403) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:360) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.boot.availability.AvailabilityChangeEvent.publish(AvailabilityChangeEvent.java:81) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.boot.availability.AvailabilityChangeEvent.publish(AvailabilityChangeEvent.java:67) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.doClose(ServletWebServerApplicationContext.java:167) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.context.support.AbstractApplicationContext.close(AbstractApplicationContext.java:978) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.boot.SpringApplication.handleRunFailure(SpringApplication.java:814) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.boot.SpringApplication.run(SpringApplication.java:325) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE] 在 crud.example.application.Application.main(Application.java:10) ~[classes/:na] 原因： org.springframework.beans.factory.NoSuchBeanDefinitionException: 否 'org.springframework.core.env.Environment' 类型的限定 bean 可用：预计至少有 1 个符合 autowire 条件的 bean 候选人。依赖注解：{} at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1716) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1272) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1226) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:885) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:789) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE] ... 23个常用框架省略

注意： 我的项目在模型（书）的单个模型和 CRUD 操作上运行良好，但现在我想在模型中添加一个新列 (@OneToOne)，该项目可以'不开始

我的书模型：

package crud.example.application.Models;

import javax.persistence.*;

@Entity
@Table(name = "Book")
public class Book
{
    public Book(){}
    public Book(String bookName, String authorName, String count, String writeDate) {
        this.bookName = bookName;
        this.authorName = authorName;
        this.count = count;
        this.writeDate = writeDate;
    }

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column
    private int id;
    @Column
    private String bookName;
    @Column
    private String authorName;
    @Column
    private String count;
    @Column
    private String writeDate;

    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "lessonID")
    private lesson lessons;

    public lesson getLessons() {
        return lessons;
    }

    public void setLessons(lesson lessons) {
        this.lessons = lessons;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getBookName() {
        return bookName;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public String getAuthorName() {
        return authorName;
    }

    public void setAuthorName(String authorName) {
        this.authorName = authorName;
    }

    public String getCount() {
        return count;
    }

    public void setCount(String count) {
        this.count = count;
    }

    public String getWriteDate() {
        return writeDate;
    }

    public void setWriteDate(String writeDate) {
        this.writeDate = writeDate;
    }
}

我的课程模型：

@Entity
@Table(name = "lesson")
public class lesson {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column
    private int id;

    @Column(name = "name")
    private String name;

    public lesson(){}
    public lesson (String name){
        this.name = name;
    }

    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 Hibernate.cfg.xml：

<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>

        <!-- JDBC Database connection settings -->
        <property name="connection.driver_class">com.mysql.cj.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost:8080/test?useSSL=false&amp;serverTimezone=UTC</property>
        <property name="connection.username">root</property>
        <property name="connection.password">123321</property>

        <!-- JDBC connection pool settings ... using built-in test pool -->
        <property name="connection.pool_size">20</property>

        <!-- Select our SQL dialect -->
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

        <!-- Echo the SQL to stdout -->
        <property name="show_sql">true</property>

        <!-- Set the current session context -->
        <property name="current_session_context_class">thread</property>


    </session-factory>

</hibernate-configuration>

我的配置类：

@Configuration
public class config {

    @Bean
    public SessionFactory sessionFactory(){
        SessionFactory sf = new org.hibernate.cfg.Configuration().configure("hibernate.cfg.xml").addAnnotatedClass(Book.class).
                buildSessionFactory();
        return sf;
    }
}

我正在使用 IntelliJ IDE。请帮我。谢谢..:D

【问题讨论】：

尝试将您的课程类命名为Lesson.java，并将类名也命名为Lesson

标签： java mysql spring hibernate intellij-idea

【解决方案1】：

请将课程类的名称更改为大写并尝试将您的 SessionFactory bean 更改为

   @Bean
    public SessionFactory sessionFactory(){
        SessionFactory sf = new org.hibernate.cfg.Configuration()
                           .configure("hibernate.cfg.xml")
                           .addAnnotatedClass(Book.class)
                           .addAnnotatedClass(Lesson.class)
                           .buildSessionFactory();
        return sf;
    }

【讨论】：

哇，太好了，它工作正常。但我有一个问题：为什么要创建大写的课程模型？
这只是一个 Java 命名约定，类/接口名称为大写，对象、方法、变量等名称为 CamelCase。在我看来，它还有助于增强代码的可读性，因为 Lesson course=new Lesson() 清楚地将类和对象分开，不像 course=new course()
更多关于命名约定javatpoint.com/java-naming-conventions