【发布时间】：2020-08-20 13:50:57
【问题描述】：
我正在为我的学习编写一个“类似 Deezer”的应用程序，但我在映射外键时遇到了问题。这是相关的代码：
抽象类曲目列表
@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@DiscriminatorColumn(name = "list_type")
public abstract class TrackList {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int tlid;
private String name;
private String imageFileName;
@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "TrackList_Track", joinColumns = @JoinColumn(name = "tlid"), inverseJoinColumns =
@JoinColumn(name = "tid"))
@OneToMany(mappedBy = "album")
private ArrayList<Track> trackList = new ArrayList<>();
...
}
类专辑扩展了 TrackList
@Entity
@DiscriminatorValue("ALBUM")
public class Album extends TrackList {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int aid;
private LocalDate date;
@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "Album_Genre", joinColumns = @JoinColumn(name = "aid"), inverseJoinColumns =
@JoinColumn(name = "gid"))
private ArrayList<Genre> genres = new ArrayList<>();
@ManyToMany(mappedBy = "albums")
private ArrayList<Performer> performers = new ArrayList<>();
...
}
类播放列表扩展了 TrackList
@Entity
@DiscriminatorValue("PLAYLIST")
public class Playlist extends TrackList {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int plid;
private User creator;
private String description;
@ManyToMany(mappedBy = "playlists")
private ArrayList<User> users;
...
}
课堂跟踪
@Entity
public class Track {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int tid;
private String mp3FileName;
@ManyToOne
@JoinColumn(name = "tlid")
private Album album;
private int num = 0;
@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "Track_Genre", joinColumns = @JoinColumn(name = "tid"), inverseJoinColumns =
@JoinColumn(name = "gid"))
private ArrayList<Genre> genres = new ArrayList<>();
@ManyToMany(mappedBy = "tracklist")
private ArrayList<Performer> performers = new ArrayList<>();
@ManyToMany(mappedBy = "trackList")
private ArrayList<Playlist> playlists = new ArrayList<>();
}
班级类型
@Entity
public class Genre {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int gid;
private String name;
@ManyToMany(mappedBy = "genres")
private ArrayList<Track> tracks = new ArrayList<>();
@ManyToMany(mappedBy = "genres")
private ArrayList<Album> albums = new ArrayList<>();
...
}
班级表演者
@Entity
public class Performer {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int peid;
private String name;
@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "Performer_Album", joinColumns = @JoinColumn(name = "peid"), inverseJoinColumns =
@JoinColumn(name = "aid"))
private ArrayList<Album> albums = new ArrayList<>();
@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "Performer_Track", joinColumns = @JoinColumn(name = "peid"), inverseJoinColumns =
@JoinColumn(name = "tid"))
private ArrayList<Track> tracklist = new ArrayList<>();
...
}
类用户
@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "user_type")
@DiscriminatorValue("CLASSIC")
public class User {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int uid;
private String pseudo;
private String email;
private String password;
@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "User_Playlist", joinColumns = @JoinColumn(name = "uid"), inverseJoinColumns =
@JoinColumn(name = "plid"))
private ArrayList<Playlist> playlists;
...
}
这是我得到的错误：
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-05-05 20:59:00.301 ERROR 21040 --- [ main] o.s.boot.SpringApplication : Application run failed
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 org.hibernate.AnnotationException: java.util.ArrayList collection type not supported for property: org.ThePouil.projects.MyTunes.model.beans.music.TrackList.trackList
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1796) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:595) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1108) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.ThePouil.projects.MyTunesApplication.main(MyTunesApplication.java:10) [classes/:na]
Caused by: org.hibernate.AnnotationException: java.util.ArrayList collection type not supported for property: org.ThePouil.projects.MyTunes.model.beans.music.TrackList.trackList
at org.hibernate.cfg.annotations.CollectionBinder.getCollectionBinder(CollectionBinder.java:317) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:1939) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.cfg.AnnotationBinder.processIdPropertiesIfNotAlready(AnnotationBinder.java:975) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:802) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.processEntityHierarchies(AnnotationMetadataSourceProcessorImpl.java:254) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.processEntityHierarchies(MetadataBuildingProcess.java:230) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:273) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1202) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1233) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:391) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:378) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1855) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1792) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
... 16 common frames omitted
感谢您的帮助。
:: 编辑 :: 显然 Hibernate 无法处理 ArrayList 但 List 并且感谢 @AdyJunior 我删除了 @OneToMany 在 TrackList 类中的 trackList 字段上，并在 Album 类中创建一个新字段。所以我将代码更改为：
抽象类曲目列表
@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@DiscriminatorColumn(name = "list_type")
public abstract class TrackList {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int tlid;
private String name;
private String imageFileName;
@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "TrackList_Track", joinColumns = @JoinColumn(name =
"tlid"), inverseJoinColumns =
@JoinColumn(name = "tid"))
private List<Track> trackList = new ArrayList<>();
...
}
类专辑扩展了 TrackList
@Entity
@DiscriminatorValue("ALBUM")
public class Album extends TrackList {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int aid;
/* a reference to the List<Track> trackList from mother class */
/* overrided getter/setter
@OneToMany(mappedBy = "album")
private List<Track> trackList = new ArrayList<>();
private LocalDate date;
@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "Album_Genre", joinColumns = @JoinColumn(name = "aid"),
inverseJoinColumns =
@JoinColumn(name = "gid"))
private List<Genre> genres = new ArrayList<>();
@ManyToMany(mappedBy = "albums")
private List<Performer> performers = new ArrayList<>();
...
}
现在我遇到了错误：
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-05-06 11:50:05.582 ERROR 17088 --- [ main] o.s.boot.SpringApplication : Application run failed
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 java.lang.ClassCastException: org.hibernate.mapping.JoinedSubclass cannot be cast to org.hibernate.mapping.RootClass
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1796) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:595) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1108) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.ThePouil.projects.MyTunesApplication.main(MyTunesApplication.java:10) [classes/:na]
Caused by: java.lang.ClassCastException: org.hibernate.mapping.JoinedSubclass cannot be cast to org.hibernate.mapping.RootClass
at org.hibernate.cfg.annotations.PropertyBinder.bind(PropertyBinder.java:214) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.cfg.annotations.PropertyBinder.makePropertyValueAndBind(PropertyBinder.java:205) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:2282) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.cfg.AnnotationBinder.processIdPropertiesIfNotAlready(AnnotationBinder.java:975) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:802) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.processEntityHierarchies(AnnotationMetadataSourceProcessorImpl.java:254) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.processEntityHierarchies(MetadataBuildingProcess.java:230) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:273) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1202) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1233) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:391) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:378) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1855) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1792) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
... 16 common frames omitted
::EDIT 2:: 好吧，子类不能有 @ID，只有主类。 所以我从 Album class 和 Playlist class 中删除了 @ID。 这消除了先前的错误。 但现在我得到了这个：
org.hibernate.MappingException: Could not determine type for: packages.User, at table: playlist, for columns: [org.hibernate.mapping.Column(creator)]
::EDIT 3:: 要删除以前的错误：
班级播放列表
@ManyToOne
@JoinColumn(name = "uid")
private User creator;
还添加了一种将“拥有”/创建播放列表添加到用户类的方法：
@OneToMany(mappedBy = "creator")
public List<Playlist> getOwnPlaylist() {
ArrayList<Playlist> pl = new ArrayList<>();
for (Playlist p : playlists)
try {
if (isCreator(p))
pl.add(p);
} catch (UserException e) {
e.printStackTrace();
}
return pl;
}
现在出现错误：
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL "alter table playlist add constraint FKpqwn3quei4t1vlr1eh3pt4fts foreign key (uid) references user (uid)" via JDBC Statement
...
java.sql.SQLException: Failed to add the foreign key constraint. Missing index for constraint 'FKpqwn3quei4t1vlr1eh3pt4fts' in the referenced table 'user'
::EDIT 4(LAST ?):: 好吧，那是一个棘手的问题。你不能有一个名为“用户”的表，因为它是为 mysql/postgresql/etc 保留的... 要删除以前的错误：
类用户
@Entity
@Table(name = "MT_User")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "user_type")
@DiscriminatorValue("CLASSIC")
public class User {
...
}
【问题讨论】：
-
从 TrackList 类的 trackList 字段中移除 @OneToMany(mappedBy = "album")。如果您需要关联“trackList x 专辑”，则需要创建一个新字段。
-
似乎休眠的 ArrayList 类型有问题，改为 List ，现在问题似乎是你所指的。所以你说我需要创建一个新字段，但 TrackList 是一个 Abstract Class 我不想添加对大多数子类无用的字段......我该怎么办？跨度>
标签： java mysql hibernate spring-boot foreign-keys