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जेपीए में नया है और एक्लिप्ससेंक से शुरू हो रहा है। ट्यूटोरियल से मदद लेते हुए मैंने अपनी पहली जेपीए परियोजना को एक इकाई (स्वचालित रूप से जेपीए टूल्स का उपयोग करके बनाया गया) बनाने की शुरुआत की, एक साधारण मुख्य वर्ग सबसे बुनियादी चयन क्वेरी को फायरिंग करना शुरू कर दिया। हालांकि जब मैं मुख्य वर्ग को चलाने का प्रयास करता हूं तो मुझे दृढ़ता की एक पूर्वनिर्धारितता मिलती है अपूर्ण अपवाद। मैं SQL सर्वर एक्सप्रेस 2008 का उपयोग कर रहा हूँ और नमूना AdventureWorks डेटाबेस पूछताछ कर रहा हूँ। डेटाबेस से कनेक्ट करने में सक्षम हूं (डेटाबेस विकास परिप्रेक्ष्य का उपयोग कर)। विस्तृत त्रुटि लॉग और नीचे दिए कोड स्निपेट:PersistenceUnit की पूर्वनिर्धारित EclipseLink
मुख्य वर्ग
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.Persistence;
import model.Employee;
public class Main {
public static void main(String[] args) {
EntityManager em = Persistence.createEntityManagerFactory("JPA2").createEntityManager();
List<Employee> list = em.createQuery("Select * from humanresources.Employee", Employee.class).getResultList();
for(Employee e : list)
{
System.out.println(e.getBirthDate());
}
}
}
इकाई
package model;
import java.io.Serializable;
import javax.persistence.*;
import java.sql.Timestamp;
@Entity
public class Employee implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@Column(name="BusinessEntityID")
private int businessEntityID;
@Column(name="BirthDate")
private Object birthDate;
@Column(name="Gender")
private Object gender;
@Column(name="HireDate")
private Object hireDate;
@Column(name="JobTitle")
private Object jobTitle;
@Column(name="MaritalStatus");
private Object maritalStatus;
@Column(name="ModifiedDate")
private Timestamp modifiedDate;
@Column(name="NationalIDNumber")
private Object nationalIDNumber;
@Column(name="OrganizationLevel")
private short organizationLevel;
@Column(name="OrganizationNode")
private String organizationNode;
private String rowguid;
@Column(name="SickLeaveHours")
private short sickLeaveHours;
@Column(name="VacationHours")
private short vacationHours;
public Employee() {
}
public int getBusinessEntityID() {
return this.businessEntityID;
}
public void setBusinessEntityID(int businessEntityID) {
this.businessEntityID = businessEntityID;
}
public Object getBirthDate() {
return this.birthDate;
}
public void setBirthDate(Object birthDate) {
this.birthDate = birthDate;
}
public Object getGender() {
return this.gender;
}
public void setGender(Object gender) {
this.gender = gender;
}
public Object getHireDate() {
return this.hireDate;
}
public void setHireDate(Object hireDate) {
this.hireDate = hireDate;
}
public Object getJobTitle() {
return this.jobTitle;
}
public void setJobTitle(Object jobTitle) {
this.jobTitle = jobTitle;
}
public Object getMaritalStatus() {
return this.maritalStatus;
}
public void setMaritalStatus(Object maritalStatus) {
this.maritalStatus = maritalStatus;
}
public Timestamp getModifiedDate() {
return this.modifiedDate;
}
public void setModifiedDate(Timestamp modifiedDate) {
this.modifiedDate = modifiedDate;
}
public Object getNationalIDNumber() {
return this.nationalIDNumber;
}
public void setNationalIDNumber(Object nationalIDNumber) {
this.nationalIDNumber = nationalIDNumber;
}
public short getOrganizationLevel() {
return this.organizationLevel;
}
public void setOrganizationLevel(short organizationLevel) {
this.organizationLevel = organizationLevel;
}
public String getOrganizationNode() {
return this.organizationNode;
}
public void setOrganizationNode(String organizationNode) {
this.organizationNode = organizationNode;
}
public String getRowguid() {
return this.rowguid;
}
public void setRowguid(String rowguid) {
this.rowguid = rowguid;
}
public short getSickLeaveHours() {
return this.sickLeaveHours;
}
public void setSickLeaveHours(short sickLeaveHours) {
this.sickLeaveHours = sickLeaveHours;
}
public short getVacationHours() {
return this.vacationHours;
}
public void setVacationHours(short vacationHours) {
this.vacationHours = vacationHours;
}
}
Persistence.XML (मेटा-INF फ़ोल्डर के अंतर्गत)
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
<persistence-unit name="JPA2" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>model.Employee</class>
<properties>
<property name="eclipselink.target-database" value="SQLServer"/>
<property name="javax.persistence.jdbc.url" value="jdbc:sqlserver://localhost:1433;databaseName=AdventureWorks2008"/>
<property name="javax.persistence.jdbc.user" value="Username"/>
<property name="javax.persistence.jdbc.password" value="Username"/>
<property name="javax.persistence.jdbc.driver" value="com.microsoft.sqlserver.jdbc.SQLServerDriver"/>
</properties>
</persistence-unit>
अपवाद
Exception in thread "main" Local Exception Stack:
Exception [EclipseLink-30005] (Eclipse Persistence Services - 2.4.2.v20130514- 5956486): org.eclipse.persistence.exceptions.PersistenceUnitLoadingException
Exception Description: An exception was thrown while searching for persistence archives with ClassLoader: [email protected]
Internal Exception: javax.persistence.PersistenceException: Exception [EclipseLink-28018] (Eclipse Persistence Services - 2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.EntityManagerSetupException
Exception Description: Predeployment of PersistenceUnit [JPA2] failed.
Internal Exception: Exception [EclipseLink-7155] (Eclipse Persistence Services - 2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.ValidationException
Exception Description: The type [class java.lang.Object] for the attribute [hireDate] on the entity class [class model.Employee] is not a valid type for a serialized mapping. The attribute type must implement the Serializable interface.
at org.eclipse.persistence.exceptions.PersistenceUnitLoadingException.exceptionSearchingForPer sistenceResources(PersistenceUnitLoadingException.java:127)
at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvi der.java:118)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:78)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54)
at Main.main(Main.java:20)
Caused by: javax.persistence.PersistenceException: Exception [EclipseLink-28018] (Eclipse Persistence Services - 2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.EntityManagerSetupException
Exception Description: Predeployment of PersistenceUnit [JPA2] failed.
Internal Exception: Exception [EclipseLink-7155] (Eclipse Persistence Services - 2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.ValidationException
Exception Description: The type [class java.lang.Object] for the attribute [hireDate] on the entity class [class model.Employee] is not a valid type for a serialized mapping. The attribute type must implement the Serializable interface.
at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.createPredeployFailedPersistenc eException(EntityManagerSetupImpl.java:1556)
at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.predeploy(EntityManagerSetupImp l.java:1547)
at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.callPredeploy(JPAInitializer .java:98)
at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvi der.java:108)
... 3 more
Caused by: Exception [EclipseLink-28018] (Eclipse Persistence Services - 2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.EntityManagerSetupException
Exception Description: Predeployment of PersistenceUnit [JPA2] failed.
Internal Exception: Exception [EclipseLink-7155] (Eclipse Persistence Services - 2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.ValidationException
Exception Description: The type [class java.lang.Object] for the attribute [hireDate] on the entity class [class model.Employee] is not a valid type for a serialized mapping. The attribute type must implement the Serializable interface.
at org.eclipse.persistence.exceptions.EntityManagerSetupException.predeployFailed(EntityManage rSetupException.java:221)
... 7 more
Caused by: Exception [EclipseLink-7155] (Eclipse Persistence Services - 2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.ValidationException
Exception Description: The type [class java.lang.Object] for the attribute [hireDate] on the entity class [class model.Employee] is not a valid type for a serialized mapping. The attribute type must implement the Serializable interface.
at org.eclipse.persistence.exceptions.ValidationException.invalidTypeForSerializedAttribute(ValidationException.java:1121)
at org.eclipse.persistence.internal.jpa.metadata.converters.SerializedMetadata.process(SerializedMetadata.java:99)
at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.MappingAccessor.processSerialized(MappingAccessor.java:1807)
at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.MappingAccessor.processJPA Converters(MappingAccessor.java:1586)
at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.MappingAccessor.processMappingConverter(MappingAccessor.java:1652)
at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.MappingAccessor.processMap pingValueConverter(MappingAccessor.java:1670)
at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.BasicAccessor.process(BasicAccessor.java:414)
at org.eclipse.persistence.internal.jpa.metadata.MetadataDescriptor.processMappingAccessors(MetadataDescriptor.java:1461)
at org.eclipse.persistence.internal.jpa.metadata.accessors.classes.ClassAccessor.processMappingAccessors(ClassAccessor.java:1526)
at org.eclipse.persistence.internal.jpa.metadata.accessors.classes.EntityAccessor.processMappingAccessors(EntityAccessor.java:1085)
at org.eclipse.persistence.internal.jpa.metadata.accessors.classes.EntityAccessor.process(EntityAccessor.java:645)
at org.eclipse.persistence.internal.jpa.metadata.MetadataProject.processStage2(MetadataProject.java:1718)
at org.eclipse.persistence.internal.jpa.metadata.MetadataProcessor.processORMMetadata(MetadataProcessor.java:536)
at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.processORMetadata(PersistenceUnitProcessor.java:550)
at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.predeploy(EntityManagerSetupImpl.java:1484)
... 5 more
जैसा कि मैंने बताया है कि एंटीटी क्लास जेपीए का उपयोग करके ऑटो-जेनरेट की गई थी और इसलिए डिफ़ॉल्ट रूप से सीरियलज़ेबल लागू करता है। इसके अलावा मैंने एंटिटी क्लास को एक ही int संपत्ति में अलग करने की कोशिश की है, लेकिन अभी भी कोई भाग्य नहीं है। मैंने – Ruschel
से ऊपर के प्रश्न में एंटीटी क्लास के लिए विवरण भी जोड़े हैं, कर्मचारी के भीतर आपके सभी गुण प्रकार ऑब्जेक्ट्स प्रकार हैं जो क्रमिक नहीं हैं, और संभवतः आप जो चाहते हैं उसकी संभावना नहीं है। उदाहरण के लिए त्रुटि में उल्लिखित किराए पर लगता है जैसे यह java.sql.Date होना चाहिए – Chris