Eclipselink与jpa错误的持久性负载

Question

您好我试图将JPA与eclipse链接一起使用，但它给了我以下错误： 我使用maven，context.xml文件在web模块中，persistaence.xml在access / db模块中。

 Failed to connect to MyModalTestApp: Exception [EclipseLink-30005] (Eclipse 
 Persistence Services - 2.6.4.v20160829-44060b6): 
 org.eclipse.persistence.exceptions.PersistenceUnitLoadingException
  Exception Description: An exception was thrown while searching for 
persistence archives with ClassLoader: ParallelWebappClassLoader
context: modaltestapp-api
 delegate: false
 ----------> Parent Classloader:
 java.net.URLClassLoader@3fee733d

 Internal Exception: javax.persistence.PersistenceException: Exception 
 [EclipseLink-28018] (Eclipse Persistence Services - 2.6.4.v20160829-
 44060b6): org.eclipse.persistence.exceptions.EntityManagerSetupException
 Exception Description: Predeployment of PersistenceUnit [MyModalTestApp] 
 failed.
  Internal Exception: Exception [EclipseLink-7161] (Eclipse Persistence 
 Services - 2.6.4.v20160829-44060b6): 
 org.eclipse.persistence.exceptions.ValidationException
  Exception Description: Entity class [class 
 com.modaltestapp.entity.RegistrationEntity] has no primary key specified. 
 It should define either an @Id, @EmbeddedId or an @IdClass. If you have 
 defined PK using any of these annotations then make sure that you do not 
 have mixed access-type (both fields and properties annotated) in your 
 entity class hierarchy.

persistence.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">

 <persistence-unit name="MyModalTestApp" transaction-type="RESOURCE_LOCAL">
    <non-jta-data-source>java:comp/env/jdbc/MODALTESTAPP_DATASOURCE</non-jta-data-source>
    <class>com.modaltestapp.entity.RegistrationEntity</class>

    <exclude-unlisted-classes>true</exclude-unlisted-classes>
    <properties>
        <property name="eclipselink.ddl-generation.output-mode" value="database" />

        <property name="eclipselink.ddl-generation" value="none"/>


        <property name="eclipselink.weaving" value="static" />
        <property name="eclipselink.target-database" value="Auto"/>
        <property name="eclipselink.target-server" value="None"/>
        <property name="eclipselink.jdbc.batch-writing" value="JDBC"/>
        <property name="eclipselink.logging.level" value="FINEST"/>
        <property name="eclipselink.logging.timestamp" value="true"/>
        <property name="eclipselink.logging.session" value="false"/>
        <property name="eclipselink.logging.thread" value="true"/>
        <property name="eclipselink.logging.exceptions" value="true"/> 

        <!-- 0 is a valid ID 
        <property name="eclipselink.id-validation" value="NULL"/> -->

        <!-- We need the following, else EclipseLink cannot properly translate column names in Native SQL queries. -->
        <property name="eclipselink.jdbc.uppercase-columns" value="true"/>
    </properties>
  </persistence-unit>
</persistence>

pojo是：

  package com.modaltestapp.entity;

  import java.io.Serializable;

   import javax.persistence.Column;
   import javax.persistence.Entity;
   import javax.persistence.Table;

   @Entity
   @Table(name = "REGISTRATION")
   public class RegistrationEntity implements Serializable{

  private static final long serialVersionUID = 1L;

@Column(name = "FIRSTNAME")
private String firstName;

@Column(name = "LASTNAME")
private String lastName;

@Column(name = "LASTNAME")
private String email;

@Column(name = "MESSAGE")
private String message;

@Column(name = "EDUCATION")
private String education;

@Column(name = "HOBBIES")
private String hobbies;

@Column(name = "GENDER")
private String gender;


public String getFirstName() {
    return firstName;
}
public void setFirstName(String firstName) {
    this.firstName = firstName;
}
public String getLastName() {
    return lastName;
}
public void setLastName(String lastName) {
    this.lastName = lastName;
}
public String getEmail() {
    return email;
}
public void setEmail(String email) {
    this.email = email;
}
public String getMessage() {
    return message;
}
public void setMessage(String message) {
    this.message = message;
}
public String getEducation() {
    return education;
}
public void setEducation(String education) {
    this.education = education;
}
public String getHobbies() {
    return hobbies;
}
public void setHobbies(String hobbies) {
    this.hobbies = hobbies;
}
public String getGender() {
    return gender;
}
public void setGender(String gender) {
    this.gender = gender;
}


}

context.xml是：

 <Context>

<!-- Default set of monitored resources -->
<WatchedResource>WEB-INF/web.xml</WatchedResource>

<!-- Uncomment this to disable session persistence across Tomcat restarts -->
<!--
<Manager pathname="" />
-->

<!-- Uncomment this to enable Comet connection tacking (provides events
     on session expiration as well as webapp lifecycle) -->
<!--
<Valve className="org.apache.catalina.valves.CometConnectionManagerValve" />
-->


<Resource name="jdbc/MODALTESTAPP_DATASOURCE" auth="Container" type="javax.sql.DataSource"
          maxTotal="8" maxIdle="2"
          username="root" password="unnati@123" driverClassName="com.mysql.jdbc.Driver"
          url="jdbc:mysql://localhost:3306/MODALTESTAPP" validationQuery="select 1"/>


  </Context>

我的实现代码是：

  try {
    EntityManager em = Persistence.createEntityManagerFactory("MyModalTestApp").createEntityManager();
    System.out.println("in database portion1");
    /* Persist entity */
    em.getTransaction().begin();
    System.out.println("in database portion2");
    em.persist(REG);
    System.out.println("in database portion3");
    em.getTransaction().commit();
    System.out.println("yes transcaction done");
    } catch (Exception e) {
           System.out.println("Failed to connect to MyModalTestApp: " + e);

    //            e.printStackTrace();
      }