在我决定添加评论之前，我的 Web 应用程序一直在运行。我把它搞砸了很多，所以我将 spring.jpa.hibernate.ddl-auto 从 upate 更改为 create-drop
但是现在，当我 spring.jpa.hibernate.ddl-auto = create-drop 应用程序启动时，当我将其更改为 spring.jpa.hibernate.ddl-auto = update 我得到这个错误:
2017-11-27 15:27:02.481 ERROR 3552 --- [ restartedMain] o.s.boot.SpringApplication : Application startup failed
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-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1078) ~[spring-context-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857) ~[spring-context-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) ~[spring-context-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.5.8.RELEASE.jar:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.8.RELEASE.jar:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.8.RELEASE.jar:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.8.RELEASE.jar:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.8.RELEASE.jar:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.8.RELEASE.jar:1.5.8.RELEASE]
at blog.BlogApplication.main(BlogApplication.java:14) [classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_111]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_111]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_111]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_111]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-1.5.8.RELEASE.jar:1.5.8.RELEASE]
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-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:353) ~[spring-orm-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:370) ~[spring-orm-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:359) ~[spring-orm-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) ~[spring-beans-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) ~[spring-beans-4.3.12.RELEASE.jar:4.3.12.RELEASE]
... 21 common frames omitted
Caused by: org.hibernate.tool.schema.spi.SchemaManagementException: Unable to execute schema management to JDBC target [alter table comments add constraint FK99rehd3fcds7jsy5dpa39fitm foreign key (comments) references users (id)]
at org.hibernate.tool.schema.internal.TargetDatabaseImpl.accept(TargetDatabaseImpl.java:59) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
at org.hibernate.tool.schema.internal.SchemaMigratorImpl.applySqlString(SchemaMigratorImpl.java:431) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
at org.hibernate.tool.schema.internal.SchemaMigratorImpl.applySqlStrings(SchemaMigratorImpl.java:420) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
at org.hibernate.tool.schema.internal.SchemaMigratorImpl.applyForeignKeys(SchemaMigratorImpl.java:386) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
at org.hibernate.tool.schema.internal.SchemaMigratorImpl.doMigrationToTargets(SchemaMigratorImpl.java:214) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
at org.hibernate.tool.schema.internal.SchemaMigratorImpl.doMigration(SchemaMigratorImpl.java:60) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:134) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:101) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:472) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:444) ~[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]
... 27 common frames omitted
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: BLOB/TEXT column 'comments' used in key specification without a key length
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_111]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_111]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_111]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_111]
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at com.mysql.jdbc.Util.getInstance(Util.java:408) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:943) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3973) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3909) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2527) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2680) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2483) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1552) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2607) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1480) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_111]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_111]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_111]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_111]
at org.apache.tomcat.jdbc.pool.StatementFacade$StatementProxy.invoke(StatementFacade.java:114) ~[tomcat-jdbc-8.5.23.jar:na]
at com.sun.proxy.$Proxy88.executeUpdate(Unknown Source) ~[na:na]
at org.hibernate.tool.schema.internal.TargetDatabaseImpl.accept(TargetDatabaseImpl.java:56) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
... 37 common frames omitted
可能我的一些关系搞砸了，但我有一个 ArticleBindingModel
public class ArticleBindingModel
{
private String comments;
@NotNull
private String title;
@NotNull
private String content;
//--------------------------GETTERS/SETTERS---------------------------
public String getTitle()
{
return title;
}
public void setTitle(String title)
{
this.title = title;
}
public String getContent()
{
return content;
}
public void setContent(String content)
{
this.content = content;
}
public String getComments()
{
return comments;
}
public void setComments(String comments)
{
this.comments = comments;
}
}
文章实体
@Entity
@Table(name = "articles")
public class Article
{
private Integer id;
private String title;
private String content;
private User author;
private User commenter;
private Set<Comment> comments;
//-----------------------------CONSTRUCTORS--------------------------
public Article(String title, String content, User author)
{
this.title = title;
this.content = content;
this.author = author;
this.comments = new HashSet<>();
}
public Article(){}
//-------------------------GETTERS/SETTERS----------------------------
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
public Integer getId()
{
return id;
}
public void setId(Integer id)
{
this.id = id;
}
@Column(nullable = false)
public String getTitle()
{
return title;
}
public void setTitle(String title)
{
this.title = title;
}
@Column(columnDefinition = "text", nullable = false)
public String getContent()
{
return content;
}
public void setContent(String content)
{
this.content = content;
}
@ManyToOne()
@JoinColumn(nullable = false, name = "authorId")
public User getAuthor()
{
return author;
}
public void setAuthor(User author)
{
this.author = author;
}
@OneToMany(mappedBy = "article")
public Set<Comment> getComments()
{
return comments;
}
public void setComments(Set<Comment> comments)
{
this.comments = comments;
}
}
评论实体
@Entity
@Table(name = "comments")
public class Comment
{
private Integer id;
private User commenter;
private String comments;
private Article article;
//-----------------------------CONSTRUCTORS----------------------
public Comment(User commenter, String comments, Article article)
{
this.commenter = commenter;
this.comments = comments;
this.article = article;
}
public Comment(){}
//----------------------METHODS-----------------------------------
//--------------------GETTERS/SETTERS-----------------------------
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
public Integer getId()
{
return id;
}
public void setId(Integer id)
{
this.id = id;
}
@Column(nullable = false, columnDefinition = "LONGBLOB")
public String getComments()
{
return comments;
}
public void setComments(String comments)
{
this.comments = comments;
}
@ManyToOne()
@JoinColumn(nullable = false, name = "commenterId")
public User getCommenter()
{
return commenter;
}
public void setCommenter(User commenter)
{
this.commenter = commenter;
}
@ManyToOne()
@JoinColumn(nullable = false, name = "articleId")
public Article getArticle()
{
return article;
}
public void setArticle(Article article)
{
this.article = article;
}
}
用户实体
@Entity
@Table(name = "users")
public class User
{
private Integer id;
private String username;
private Set<Article> articles;
private Set<Comment> comments;
//-----------------------------------CONSTRUCTORS-----------------------------------
public User (String username)
{
this.username = username;
this.articles = new HashSet<>();
this.comments = new HashSet<>();
}
public User() {
}
//------------------------------------METHODS------------------------------------------
//----------------------------------GETTERS/SETTERS--------------------------------------
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
public Integer getId()
{
return id;
}
public void setId(Integer id)
{
this.id = id;
}
@Column(name = "username", length = 80, nullable = false, unique = true)
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
@OneToMany(mappedBy = "author")
public Set<Article> getArticles()
{
return articles;
}
public void setArticles(Set<Article> articles)
{
this.articles = articles;
}
@OneToMany(mappedBy = "comments")
public Set<Comment> getComments()
{
return comments;
}
public void setComments(Set<Comment> comments)
{
this.comments = comments;
}
}
然后我有一个适当实体的存储库。我对代码进行了大量编辑，所以我不会成为一个“heresallmycode”的人。但是，我很确定我的注释关系是问题所在。我希望评论与文章具有多对一关系，在评论发布时会出现在评论上方的用户以及反向一对多关系文章的评论。当使用 create 参数创建表时，我的文章表没有清空(我之前在 update 上有它)，我不得不手动删除它。现在，创建表时它是空的。我认为这值得一提。如果需要的话，我可以发布create 日志。
编辑
我忘记了我的 ArticleController
@Controller
public class ArticleController
{
@Autowired
private ArticleRepository articleRepository;
@Autowired
private UserRepository userRepository;
@Autowired
private CommentRepository commentRepository;
//---------------------------------METHODS-----------------------
//ARTICLE DETAILS--------------------------------------------------
@GetMapping("/article/{id}")
public String details(Model model, @PathVariable Integer id)
{
if (!this.articleRepository.exists(id))
{
return "redirect:/";
}
UserDetails principal = (UserDetails) SecurityContextHolder.getContext().getAuthentication().getPrincipal();//This was inside the IF
if (!(SecurityContextHolder.getContext().getAuthentication() instanceof AnonymousAuthenticationToken))
{
User entityUser = this.userRepository.findByEmail(principal.getUsername());
model.addAttribute("user", entityUser);
}
//Getting the article
Article article = this.articleRepository.findOne(id);
//Comments
Set<Comment> comments = this.commentRepository.findCommentsByArticleId(id);//findAllByArticlesId
//Set<User> commenters = this.userRepository.findAllByComments(comments);
//Models
model.addAttribute("article", article);
//model.addAttribute("commenters", commenters);
model.addAttribute("comments", comments);
model.addAttribute("view", "article/details");
return "base-layout";
}
@PostMapping("/article/{id}")
@PreAuthorize("isAuthenticated()")
public String detailsProcess(@PathVariable Integer id, ArticleBindingModel articleBindingModel)
{
if (!this.articleRepository.exists(id))
{
return "redirect:/";
}
//Getting the article
Article article = this.articleRepository.findOne(id);
//Getting the commenter
UserDetails principal = (UserDetails) SecurityContextHolder.getContext().getAuthentication().getPrincipal();
User commenter = this.userRepository.findByEmail(principal.getUsername());
//Setting the values for the comment section
return "redirect:/article/{id}";
}
}
最佳答案
您在 Comment 中将与 User 的关系定义为:
@ManyToOne()
@JoinColumn(nullable = false, name = "commenterId")
public User getCommenter()
{
return commenter;
}
但您指的是关系的 Comment 端的 comments 字符串列。您应该将 mappedBy 更改为:
@OneToMany(mappedBy = "commenter")
public Set<Comment> getComments()
{
return comments;
}
关于java - 设置为更新时，Spring Boot mvc java 应用程序无法运行，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47512550/