オブジェクト：既知のエンティティタイプではありません。 Eclipselink

Question

私はeclipselinkまたはjpaを初めて利用しています。私はhereからeclipselinkのチュートリアルに従っていました。 Test.javaクラスを実行すると、次の例外が発生します。私はネットワーク上でOracleデータベースを使用しています。私を助けてください。

[EL Info]: connection: 2016-09-14 15:13:33.562--ServerSession(271944754)--/file:/D:/Developer/EclipseLink/bin/_TestPersistence login successful 
[EL Warning]: metamodel: 2016-09-14 15:13:33.577--The collection of metamodel types is empty. Model classes may not have been found during entity search for Java SE and some Java EE container managed persistence units. Please verify that your entity classes are referenced in persistence.xml using either <class> elements or a global <exclude-unlisted-classes>false</exclude-unlisted-classes> element 
Exception in thread "main" java.lang.IllegalArgumentException: Object: Employee [name=Mukesh, email=m@gmail.com , department=Finance] is not a known Entity type. 
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:4226) 
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.persist(EntityManagerImpl.java:507) 
    at com.assignment.Test.main(Test.java:28) 

persistence.xmlの

<?xml version="1.0" encoding="UTF-8" ?> 
<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" 
version="2.0" xmlns="http://java.sun.com/xml/ns/persistence"> 
<persistence-unit name="TestPersistence" 
transaction-type="RESOURCE_LOCAL"> 
<class>com.assignment.Employee</class> 
<properties> 
<property name="javax.persistence.jdbc.driver" value="oracle.jdbc.driver.OracleDriver" /> 
<property name="javax.persistence.jdbc.url" 
value="jdbc:oracle:thin:@ipaddress:port/servicename" /> 
<property name="javax.persistence.jdbc.user" value="username" /> 
<property name="javax.persistence.jdbc.password" 
value="password" /> 
<!-- EclipseLink should create the database schema automatically --> 
<property name="eclipselink.ddl-generation" value="create-tables" /> 
<property name="eclipselink.ddl-generation.output-mode" 
value="database" /> 
</properties> 
</persistence-unit> 
</persistence> 

Employee.java

package com.assignment; 
public class Employee { 
     private Long id; 
     private String name; 
     private String email; 
     private String department; 

     public Long getId() { 
      return id; 
     } 
     public void setId(Long id) { 
      this.id = id; 
     } 
     public String getName() { 
      return name; 
     } 
     public void setName(String name) { 
      this.name = name; 
     } 
     public String getEmail() { 
      return email; 
     } 
     public void setEmail(String email) { 
      this.email = email; 
     } 
     public String getDepartment() { 
      return department; 
     } 
     public void setDepartment(String department) { 
      this.department = department; 
     } 
     public String toString() { 
      return "Employee [name=" + name + ", email=" + email + " , department=" 
        + department + "]"; 
     } 
} 

Test.java

package com.assignment; 

import java.util.List; 
import javax.persistence.EntityManager; 
import javax.persistence.EntityManagerFactory; 
import javax.persistence.Persistence; 
import javax.persistence.Query; 

public class Test { 
    private static final String PERSISTENCE_UNIT_NAME = "TestPersistence"; 
     private static EntityManagerFactory factory; 
     public static void main(String[] args) { 
     factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME); 
     EntityManager em = factory.createEntityManager(); 
     em.getTransaction().begin(); 
     Employee emp = new Employee(); 
     emp.setName("Mukesh"); 
     emp.setEmail("m@gmail.com"); 
     emp.setDepartment("Finance"); 
     em.persist(emp); 
     em.getTransaction().commit(); 
     em.close(); 
     } 
    } 

パッケージ構造

Answer 1

はEmployeeクラスのjavax.persistence.Entityのアノテーションを使用してみてください。

詳しい情報とのEclipseLink使用例： https://wiki.eclipse.org/EclipseLink/Examples/JPA

Answer 2

は、あなたのクラスに@Entityアノテーションを付けます。プライマリキーIdが必要な場合もあります。属性の1つに@Idを指定します。

package com.assignment; 

import javax.persistence.Entity; 
import javax.persistence.Id; 

@Entity 
public class Employee { 
     @Id 
     private Long id; 
     private String name; 
     private String email; 
     private String department; 

     public Long getId() { 
      return id; 
     } 
     public void setId(Long id) { 
      this.id = id; 
     } 
     public String getName() { 
      return name; 
     } 
     public void setName(String name) { 
      this.name = name; 
     } 
     public String getEmail() { 
      return email; 
     } 
     public void setEmail(String email) { 
      this.email = email; 
     } 
     public String getDepartment() { 
      return department; 
     } 
     public void setDepartment(String department) { 
      this.department = department; 
     } 
     public String toString() { 
      return "Employee [name=" + name + ", email=" + email + " , department=" 
        + department + "]"; 
     } 
}