org.hibernate.id.IdentifierGenerationException：将数据保存在一对一映射中

Question

我试图将数据保存到数据库（将两个表映射到One-To-One映射中）。

我正在使用Hibernate，Struts2和MySQL数据库。

保存数据则显示以下异常：

org.hibernate.id.IdentifierGenerationException：试图从空一到一个属性分配ID

Atom.hbm .XML

<class name="hibernetMappings.Atom" table="atom" catalog="xrcwrn_sms"> 
    <id name="id" type="java.lang.Integer"> 
     <column name="id" /> 
     <generator class="identity" /> 
    </id> 
    <property name="name" type="string"> 
     <column name="name" length="200" unique="true" /> 
    </property> 
    <property name="type" type="string"> 
     <column name="type" length="100" not-null="true" /> 
    </property> 
    <one-to-one name="page" class="hibernetMappings.Pages" cascade="save-update"> 
    </one-to-one> 
</class> 

pages.hbm.xml

<class name="hibernetMappings.Pages" table="pages" catalog="xrcwrn_sms"> 
    <id name="id" type="java.lang.Integer"> 
     <column name="id" /> 
     <generator class="foreign"> 
      <param name="property">atom</param> 
     </generator> 
    </id> 
    <one-to-one name="atom" class="hibernetMappings.Atom" 
         constrained="true"> 
    </one-to-one> 
    <property name="name" type="string"> 
     <column name="name" length="100" /> 
    </property> 
</class> 

Atom.java

public class Atom implements java.io.Serializable { 

    private Integer id; 
    private String name; 
    private String type; 
    private Pages page; 

    //getters setters and constructor 
} 

在Pages.java

public class Pages implements java.io.Serializable { 
    private int id; 
    private Atom atom; 
    private String name; 
    //getter setter and constructor 
} 

在JSP

<s:form action="createPage" method="post"> 
    Display Type <s:textfield name="atom.type" /> 
    Display Name <s:textfield name="atom.name" /> 
    Name of page <s:textfield name="atom.page.name" /> 

    <s:submit value="Create" /> 
</s:form> 

在行动

public class pageAction extends ActionSupport implements ModelDriven<Atom> { 

    Atom atom = new Atom(); 

    public String newPage() { 
     System.out.println("In action"); 
     PageDAO pd=new PageDAO(); 
     pd.insertPage(getAtom()); 
     return SUCCESS; 
    } 

    public Atom getAtom() { 
     return atom; 
    } 

    public void setAtom(Atom atom) { 
     this.atom = atom; 
    } 

    @Override 
    public Atom getModel() {  
     return atom;  
    } 
} 

在DAO

public class PageDAO { 
    public void insertPage(Atom atom) { 

      System.out.println("In Dao"); 
      Session session = HibernateUtil.getSessionFactory().openSession(); 
      session.beginTransaction(); 
      Pages page = new Pages(); 
      page.setAtom(atom); 
      session.save(atom); 
      session.getTransaction().commit(); 
      System.out.println("Done"); 
    } 
} 

完整堆栈跟踪：

SEVERE: org.hibernate.exception.GenericJDBCException: could not insert: [hibernetMappings.Atom] 
    at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:140) 
    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:128) 
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) 
    at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:63) 
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2346) 
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2853) 
    at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:71) 
    at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273) 
    at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:320) 
    at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:203) 
    at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:129) 
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:210) 
    at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:56) 
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:195) 
    at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:50) 
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93) 
    at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:713) 
    at org.hibernate.impl.SessionImpl.save(SessionImpl.java:701) 
    at org.hibernate.impl.SessionImpl.save(SessionImpl.java:697) 
    at page.PageDAO.insertPage(PageDAO.java:31) 
    at page.pageAction.newPage(pageAction.java:22) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:606) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:450) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:289) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:252) 
    at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167) 
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265) 
    at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68) 
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239) 
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239) 
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171) 
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:161) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) 
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54) 
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:563) 
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77) 
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160) 
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734) 
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673) 
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174) 
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:357) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260) 
    at com.sun.enterprise.v3.service 
SEVERE: s.impl.ContainerMapper.service(ContainerMapper.java:188) 
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191) 
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168) 
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189) 
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119) 
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288) 
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206) 
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136) 
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114) 
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77) 
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838) 
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113) 
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115) 
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55) 
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135) 
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564) 
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544) 
    at java.lang.Thread.run(Thread.java:744) 
Caused by: java.sql.SQLException: Lock wait timeout exceeded; try restarting transaction 
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1073) 
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3593) 
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3525) 
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1986) 
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2140) 
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2626) 
    at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2111) 
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2407) 
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2325) 
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2310) 
    at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:93) 
    at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:56) 
    ... 98 more 

Answer 1

您发布的堆栈跟踪不是起源IdentifierGenerationException相同。发布的堆栈跟踪意味着某人正在锁定您的事务要写入的数据库表。

如果这是一个开发数据库，​​很可能它是一个像My SQL工作台那样的SQL GUI客户端，它有一个尚未提交的打开的事务。它也可能是一个你认为你遇害的过程，现在还在。

要排除此故障，请终止所有java进程，然后使用MySql工作台或同等工作，查看是否有任何进程连接到数据库。如果您在数据库中拥有管理员权限，则也可以手动终止会话，这将释放锁。

对于IdentifierGenerationException问题，你需要做的：

page.setAtom(atom); 
atom.setPage(page); 

这样做的原因是，在一到一个关系的外键生成需要他们重点从一个实体，并使用相同的值作为一个表主键的另一个实体的键也是另一个表的外键。

在这种情况下，属性atom.setPage()为空，并且休眠尝试将该页的密钥从Page复制到Atom，但atom.getPage()为空，导致您发布错误消息。另请参阅此answer和此tutorial。