Question

我有3个关联一对多的课程，我需要获取渴望，因为如果不是它的剂量'加载我的功能列表和任务列表项目 - 功能 - 任务这是我的班级项目

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


    private static final long serialVersionUID = 1L ;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "ID", nullable = false)
    private int id;
    @Column(name = "nomProjet", nullable = true)
    private String nameProject;
    @Column(name = "etatProject", nullable = true)
    private String etatProject;

    @OneToMany(cascade = CascadeType.ALL, targetEntity = com.Model.feature.class,fetch=FetchType.EAGER)
    private List<Feature> features = new ArrayList<Feature>() ;

和我的课程专题

@Entity
@Table(name = "feature ")
public class feature implements Serializable{
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "idfeature", nullable = false)
    private int idfeature;
    @Column(name = "namefeature", nullable = true)
    private String namefeature;



    @OneToMany(cascade = CascadeType.ALL, targetEntity = com.Task.class,fetch=FetchType.EAGER)
    private List<Task> task = new ArrayList<Task>() ;
}

和我的班级任务

@Entity
@Table(name = "Task")
public class Task implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "idTask", nullable = false)
    private int idTask;
    @Column(name = "nameTask", nullable = true)
    private String nameTask;
}

当我运行我的项目时，我发现此错误

  ERROR (org.springframework.web.context.ContextLoader:220) - Context initialization failed

    org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [applicationContext-jpa.xml]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: testPU] Unable to build EntityManagerFactory
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1455)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
        at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1105)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:915)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:472)
        at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:276)
        at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:197)
        at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:47)
        at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:530)
        at org.mortbay.jetty.servlet.Context.startContext(Context.java:135)
        at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1218)
        at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:500)
        at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448)
        at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
        at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:147)
        at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:161)
        at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
        at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:147)
        at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
        at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:117)
        at org.mortbay.jetty.Server.doStart(Server.java:217)
        at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
        at org.mortbay.jetty.plugin.Jetty6PluginServer.start(Jetty6PluginServer.java:132)
        at org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty(AbstractJettyMojo.java:345)
        at org.mortbay.jetty.plugin.AbstractJettyMojo.execute(AbstractJettyMojo.java:286)
        at org.mortbay.jetty.plugin.AbstractJettyRunMojo.execute(AbstractJettyRunMojo.java:204)
        at org.mortbay.jetty.plugin.Jetty6RunMojo.execute(Jetty6RunMojo.java:183)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
        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 org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)

任何帮助，请

Answer 1

解决方案是将agetr oneToMany： @LazyCollection（LazyCollectionOption.FALSE）并删除：取= FetchType.EAGER

Answer 2

使用JPA2，您无法一次加载FetchType.EAGER 一个 List。

您可以BTW加载更多Set s，因此将List中的一个或两个转换为Set可以解决问题。除此之外甚至还有more solutions。

注意：您找到的解决方案是混合的，因为它是一个Hibernate注释，而不是JPA2注释。我通常不会将它们混合在一起，尽管没有什么真的错误。

加载具有热切关联的entitymanagerFactory

2 个答案: