java - Spring 数据jpa : Error creating bean with name 'entityManagerFactory'

Question

大家好，我是 stackoverflow 的新手，也是 spring data jpa 的新手。

我目前正在开发一个个人网站，但遇到了问题。

我正在使用:

Java8 Spring 启动1.5.2Spring Boot 入门数据 jpa 1.5.2 和MySQL 连接器

当我只有一个 @Entity 时，它工作正常，Hibernate 成功创建 MySQL 模式，但是当添加一些具有关系的 @Entity 时，我收到此错误:

    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 javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628) ~[spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1081) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:856) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:737) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:370) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:314) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1162) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1151) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at fr.geekads.Application.main(Application.java:10) [classes/:na]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.persistenceException(EntityManagerFactoryBuilderImpl.java:954) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:882) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60) ~[spring-orm-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:353) ~[spring-orm-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:370) ~[spring-orm-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:359) ~[spring-orm-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) ~[spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) ~[spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    ... 16 common frames omitted
Caused by: org.hibernate.MappingException: Could not determine type for: java.util.List, at table: user, for columns: [org.hibernate.mapping.Column(ads)]
    at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:431) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:398) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.mapping.Property.isValid(Property.java:225) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:595) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.mapping.RootClass.validate(RootClass.java:265) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.boot.internal.MetadataImpl.validate(MetadataImpl.java:329) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:443) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:879) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final]
    ... 22 common frames omitted

这是我的代码结构:

structure

pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>fr.geekads</groupId>
    <artifactId>geekads</artifactId>
    <version>1.0.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.2.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

用户.java:

@Entity
@Table(name = "User")
public class User {
    @Id
    private String email;

    private String pseudo;
    private String password;
    private String avatarURL;
    private String registerDate;
    private String description;
    private String geographicArea;
    private String lastConnexion;

    private Boolean showContact;
    private String skype;
    private String facebook;
    private String twitter;
    private String linkedin;

    private int geekCoins;

    private Project project;
    private List<Ad> ads;
    private List<Comment> comments;
}

项目.java:

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

    @Id
    private String name;

    private String logoUrl;
    private String shortDescription;
    private String description;
    private String projectUrl;

    private Boolean showContact;
    private String skype;
    private String facebook;
    private String twitter;
    private String linkedin;
    private String mail;

    @OneToOne
    private ProjectCategory category;

    @OneToOne
    private User owner;

    @OneToMany
    private List<User> members;

    @OneToMany
    private List<Ad> ads;

    private int geekCoins;
    private int views;
}

评论.java:

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

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @OneToOne//(cascade = CascadeType.ALL, targetEntity = User.class)
    private User user;

    private String message;
    private String postDate;

    @OneToOne(targetEntity = Ad.class)
    private Long ad_id;
}

和 Ad.java:

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

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private String logical_id;
    private String title;
    private String logoUrl;
    private String shortDescription;
    private String description;

    @OneToOne
    private AdCategory category;

    private String postDate;
    private String lastUp;

    private Boolean putMoneyIntoPlay;

    private int geekCoins;
    private int views;

    @OneToOne
    private User user;

    @OneToOne
    private Project project;

    private Boolean allowComments;

    @OneToMany
    private List<Comment> comments;

    @OneToOne
    private AdType type;

    private String bannerUrl;
    private String startDate;
    private String endDate;
}

我不明白为什么会收到此错误...我正在寻找解决方案 2 天...

如果您有想法，请提前感谢您的帮助

Answer 1

我终于找到了解决办法。这是我的错。

说明:

我正在考虑对象而不是关系数据库方面。

例如，在我的 User.java 中，我与 Ad.java 存在关系，而在我的 Ad.java 中，我与 User.java 存在关系，导致笛卡尔积。因此 Hibernate 无法创建 SQL 架构。

所以我根据我的概念数据模型重构了我的代码，它工作得很好。

现在，User.java 不再引用 Ad.java，并且 Ad.java 使用 @OneToOne 引用 User.java 的 @id。

问题解决了! :)