エラーメッセージ 'class'が 'generator'要素に表示されている必要があります

Question

問題：

1）教師が多くの科目を教えることができるエンティティの教師があるとします。

2）教師（名前、件名）は複合キーです。

3）サブジェクトは、親サブジェクトとして別のサブジェクトを持っています。

解決策： 私は2点を実装しましたが、3点目でエラーが発生しています。以下は

Can anyone guide me how to correct it?

次のコード

public class Client { 

public static void main(String args[]) 
{ 

Configuration cfg = new Configuration(); 
cfg.configure("hibernate.cfg.xml"); 

SessionFactory factory = cfg.buildSessionFactory(); 
Session session = factory.openSession(); 
//parent object 
Teacher t =new Teacher(); 
t.setTeacherId(101); 
t.setTeacherName("A"); 
//creating 3 child objects 
Subject s1=new Subject(); 
s1.setSubjectId(1); 
s1.setSubjectName("JSE"); 
Subject s2=new Subject(); 
s2.setSubjectId(505); 
s2.setSubjectName("JEE"); 
Subject s3=new Subject(); 
s3.setSubjectId(506); 
s3.setSubjectName("Spring"); 
// adding child objects to set, as we taken 3rd property set in parent 
Set s=new HashSet(); 
s.add(s1); 
s.add(s2); 
s.add(s3); 
t.setSubjects(s); 
Transaction tx = session.beginTransaction(); 
session.save(t); 
tx.commit(); 
session.close(); 
System.out.println("One To Many is Done..!!"); 
factory.close(); 
} 
} 


public class Subject implements Serializable{ 

private int subjectId; 
private String subjectName; 
private int forevenId; 
public int getSubjectId() { 
return subjectId; 
} 
public void setSubjectId(int subjectId) { 
this.subjectId = subjectId; 
} 
public String getSubjectName() { 
return subjectName; 
} 
public void setSubjectName(String subjectName) { 
this.subjectName = subjectName; 
} 
public int getForevenId() { 
return forevenId; 
} 
public void setForevenId(int forevenId) { 
this.forevenId = forevenId; 
} 
} 

public class Teacher implements Serializable{ 

private int teacherId; 
private String teacherName; 
private Set subjects; 
public int getTeacherId() { 
return teacherId; 
} 
public void setTeacherId(int teacherId) { 
this.teacherId = teacherId; 
} 
public String getTeacherName() { 
return teacherName; 
} 
public void setTeacherName(String teacherName) { 
this.teacherName = teacherName; 
} 
public Set getSubjects() { 
return subjects; 
} 
public void setSubjects(Set subjects) { 
this.subjects = subjects; 
} 
} 

public class Parent { 
private int subjectId; 
private String parentSubjectName; 
private Subject s; 
public Subject getS() { 
    return s; 
} 
public void setS(Subject s) { 
    this.s = s; 
} 
public int getSubjectId() { 
    return subjectId; 
} 
public void setSubjectId(int subjectId) { 
    this.subjectId = subjectId; 
} 
public String getParentSubjectName() { 
    return parentSubjectName; 
} 
public void setParentSubjectName(String parentSubjectName) { 
    this.parentSubjectName = parentSubjectName; 
} 
} 

---

Subject.hbm.xml

---

Parent.hbm.xml

---

です

Teacher.hbm.xml

エラー：

---

Exception in thread "main" org.hibernate.boot.InvalidMappingException: Could not parse mapping document: Parent.hbm.xml (RESOURCE) 
at org.hibernate.boot.jaxb.internal.InputStreamXmlSource.doBind(InputStreamXmlSource.java:46) 
at org.hibernate.boot.jaxb.internal.UrlXmlSource.doBind(UrlXmlSource.java:36) 
at org.hibernate.boot.spi.XmlMappingBinderAccess.bind(XmlMappingBinderAccess.java:59) 
at org.hibernate.boot.MetadataSources.addResource(MetadataSources.java:274) 
at org.hibernate.boot.cfgxml.spi.MappingReference.apply(MappingReference.java:70) 
at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:413) 
at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87) 
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691) 
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:723) 
at str.OurLogic.main(OurLogic.java:19) 
Caused by: org.hibernate.boot.MappingException: Unable to perform unmarshalling at line number 9 and column 12. Message: cvc-complex-type.4: Attribute 'class' must appear on element 'generator'. : origin(Parent.hbm.xml) 
at org.hibernate.boot.jaxb.internal.AbstractBinder.jaxb(AbstractBinder.java:177) 
at org.hibernate.boot.jaxb.internal.MappingBinder.doBind(MappingBinder.java:61) 
at org.hibernate.boot.jaxb.internal.AbstractBinder.doBind(AbstractBinder.java:102) 
at org.hibernate.boot.jaxb.internal.AbstractBinder.bind(AbstractBinder.java:57) 
at org.hibernate.boot.jaxb.internal.InputStreamXmlSource.doBind(InputStreamXmlSource.java:43) 
... 9 more 
Caused by: javax.xml.bind.UnmarshalException 
- with linked exception: 
[org.xml.sax.SAXParseException; lineNumber: 9; columnNumber: 12; cvc-complex-type.4: Attribute 'class' must appear on element 'generator'.] 
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.handleStreamException(UnmarshallerImpl.java:468) 
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:448) 
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:420) 
at org.hibernate.boot.jaxb.internal.AbstractBinder.jaxb(AbstractBinder.java:171) 
... 13 more 
Caused by: org.xml.sax.SAXParseException; lineNumber: 9; columnNumber: 12; cvc-complex-type.4: Attribute 'class' must appear on element 'generator'. 
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203) 
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(ErrorHandlerWrapper.java:134) 
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:437) 
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:368) 
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:325) 
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator$XSIErrorReporter.reportError(XMLSchemaValidator.java:458) 
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.reportSchemaError(XMLSchemaValidator.java:3237) 
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.addDefaultAttributes(XMLSchemaValidator.java:2943) 
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.handleStartElement(XMLSchemaValidator.java:2060) 
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.startElement(XMLSchemaValidator.java:746) 
at com.sun.org.apache.xerces.internal.jaxp.validation.ValidatorHandlerImpl.startElement(ValidatorHandlerImpl.java:570) 
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.ValidatingUnmarshaller.startElement(ValidatingUnmarshaller.java:86) 
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.InterningXmlVisitor.startElement(InterningXmlVisitor.java:60) 
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.StAXEventConnector.handleStartElement(StAXEventConnector.java:246) 
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.StAXEventConnector.bridge(StAXEventConnector.java:115) 
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:445) 
... 15 more 

Answer 1

私はクラス内の属性を使用して@JB Nizet