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我是 JPA 新手,刚开始使用 EclipseLink。在教程的帮助下,我开始创建我的第一个 JPA 项目,它包含一个实体(使用 JPA 工具自动创建),一个简单的主类,触发最基本的选择查询。但是,当我尝试运行主类时,我得到了 PersistenceUnit 的预部署失败异常。我正在使用 SQL Server Express 2008 并查询示例 AdventureWorks 数据库。能够连接到数据库(使用数据库开发视角)。详细的错误日志和代码片段如下:
主类
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());
}
}
}
实体
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(在 Meta-INF 文件夹下)
<?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>
异常
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: sun.misc.Launcher$AppClassLoader@1ac04e8
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
最佳答案
部分学习过程用于读取堆栈跟踪。您需要的行是:
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.
Employee
类是什么样的?
编辑
正如 Chris 所指出的,您的属性不是可序列化的。将日期设置为 java.util.Date、java.util.Calendar 或 java.sql.Date。前 2 个需要带有 TemporalType 的 @Temporal 注释。这些中的每一个都将允许您的示例运行,但您应该了解将存储的内容的差异。
您还应该将其他属性更改为可序列化类型,例如 jobTitle 的 String。
希望对你有帮助
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