Question

在部署我的应用程序期间，我发生了该异常。我的应用程序中有很多课程，我不知道在哪里放置@IdClass，这个例外意味着什么。我正在使用Hibernate 4.1和JBoss AS 7.1

12:10:23,761 INFO  [org.hibernate.engine.jdbc.internal.LobCreatorBuilder] (MSC service thread 1-5) HHH000424: Disabling contextual LOB creation as createClob() method threw error : java.lang.reflect.InvocationTargetException
12:10:24,075 ERROR [org.hibernate.tool.hbm2ddl.SchemaExport] (MSC service thread 1-5) HHH000389: Unsuccessful: drop sequence hibernate_sequence
12:10:24,076 ERROR [org.hibernate.tool.hbm2ddl.SchemaExport] (MSC service thread 1-5) ERROR: sequence "hibernate_sequence" does not exist
12:10:24,281 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-5) MSC00001: Failed to start service jboss.persistenceunit."kladr.ear/kladr-ejb-1.0-SNAPSHOT.jar#primary": org.jboss.msc.service.StartException in service jboss.persistenceunit."kladr.ear/kladr-ejb-1.0-SNAPSHOT.jar#primary": Failed to start service
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1767) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [rt.jar:1.6.0_35]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [rt.jar:1.6.0_35]
    at java.lang.Thread.run(Thread.java:662) [rt.jar:1.6.0_35]
Caused by: java.lang.IllegalArgumentException: expecting IdClass mapping
    at org.hibernate.ejb.metamodel.AttributeFactory$3.resolveMember(AttributeFactory.java:878)
    at org.hibernate.ejb.metamodel.AttributeFactory$4.resolveMember(AttributeFactory.java:915)
    at org.hibernate.ejb.metamodel.AttributeFactory.determineAttributeMetadata(AttributeFactory.java:423)
    at org.hibernate.ejb.metamodel.AttributeFactory.buildAttribute(AttributeFactory.java:91)
    at org.hibernate.ejb.metamodel.MetadataContext.wrapUp(MetadataContext.java:214)
    at org.hibernate.ejb.metamodel.MetamodelImpl.buildMetamodel(MetamodelImpl.java:64)
    at org.hibernate.ejb.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:91)
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:904)
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:889)
    at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:73)
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.createContainerEntityManagerFactory(PersistenceUnitServiceImpl.java:162)
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.start(PersistenceUnitServiceImpl.java:85)
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
    ... 3 more

Answer 1

@IdClass注释用于定义包含id的Class。即，这通常用于定义复合键的情况。即一个以上属性的关键复合。如果是这样的话，那就是我们这样做的方式。看一下下面的例子..我们将一个类定义为IdClass并使用@Id来定义不同的Id s for this IdClass`。

示例：

@Entity
@IdClass(AssignedRoleId.class)
public class AssignedRole
{
  @Id
  @ManyToOne
  private User userId;

  @Id
  @ManyToOne  
  private Role roleId;

  private Date dateAssigned;
}

希望这会有所帮助。

Answer 2

进一步阐述@Mukul正确答案@IdClass应该具有以下属性：

应该实现Serializable
它应该有一个带有id的构造函数（即与@Id相关联的字段）
它应该覆盖equals和hashCode

将此类作为实体的静态内部类有时非常有用，这是一个示例：

@Entity 
@IdClass(AssignedRoleId.class)
public class AssignedRole
{ 
    @Id
    @ManyToOne
    private User userId;

    @Id
    @ManyToOne
    private Role roleId;

    private Date dateAssigned;

    public static class AssignedRoleId implements Serializable {

        private User userId;
        private Role roleId;

        public AssignedRoleId() {}

        public AssignedRoleId(User userId, Role roleId) {
            this.userId = userId;
            this.roleId = roleId;
        }

        @Override
        public boolean equals(Object o) {

            if (o == this) {
                return true;
            }
            if (!(o instanceof AssignedRole)) {
                return false;
            }
            AssignedRole assignedRole = (AssignedRole) o;
            return Objects.equals(userId, assignedRole.getUserId()) &&
                   Objects.equals(roleId, assignedRole.getRoleId());
        }

        @Override
        public int hashCode() {
            return Objects.hash(userId, roleId);
        }
   }
}

Answer 3

您只能覆盖equals和hashcode，问题将得以解决，并且还需要实现java.io.Serializable

Answer 4

我遇到了同样的问题。原来我没有正确使用 Hibernate（没有 sh!t Sherlock）。我的配置文件 hibernate.cfg.xml 不包含我的实体 Java 类...我只使用 hibernate.cfg.xml 文件进行休眠配置，并且只使用 javax.persistence 注释用于我的实体类。

我刚刚在配置文件的底部添加了缺少的实体/类（总共 4 个类）并运行了我的测试代码，一切正常。

新hibernate.cfg.xml：

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
  <session-factory>
    <property name="connection.url">jdbc:oracle:thin:@localhost:1521:XE</property>
    <property name="connection.driver_class">oracle.jdbc.OracleDriver</property>
    <property name="connection.username">foo</property>
    <property name="connection.password">bar</property>
    <mapping class="test.entities.MixEntity"/>
    <mapping class="test.entities.ZutatEntity"/>
    <mapping class="test.entities.RezeptEntity"/>
    <mapping class="test.entities.MixEntityPK"/>
  </session-factory>
</hibernate-configuration>

IllegalArgumentException：期望IdClass映射

4 个答案: