Java SE上的JPA：Object：entity.Customer@5e80188f不是已知的实体类型 [英] JPA on Java SE: Object: entity.Customer@5e80188f is not a known entity type

问题描述

我正在追踪

https://glassfish.java.net/javaee5/persistence/persistence-example.html

在Java SE环境中测试JPA。
在Eclipse中，我：

to test JPA in a Java SE environment. In Eclipse, I:

• 创建了一个新的JPA（2.1）项目;


• 在选项 - > JPA->持久类管理中，我选择了自动发现注释类，而不是注释类必须在persistence.xml中列出。

我成功导入zip文件（Client.java Customer.java Order.java）中的树Java类，并修改了persistence.xml文件以满足我的需要。但是，当尝试超越主要时，我会收到以下错误。

I successfully imported the tree Java classes that are in the zip file (Client.java Customer.java Order.java) and modified the persistence.xml file to fit my needs. But I obtain the following errors when trying to excecute main.

[EL Info]: 2013-10-18 17:37:54.749--ServerSession(263489307)--EclipseLink, version: Eclipse Persistence Services - 2.5.1.v20130918-f2b9fc5
[EL Info]: connection: 2013-10-18 17:37:55.34--ServerSession(263489307)--file:/home/caterpillar/workspace/JPA_Java_SE/build/classes/_JPA_Java_SE login successful
[EL Warning]: metamodel: 2013-10-18 17:37:55.359--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: entity.Customer@5e80188f is not a known entity type.
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:4228)
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.persist(EntityManagerImpl.java:496)
    at client.Client.testInsert(Client.java:82)
    at client.Client.main(Client.java:49)

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="JPA_Java_SE">
        <properties>
            <property name="javax.persistence.logging.level" value="FINE"/>
            <property name="javax.persistence.logging.thread" value="false"/>
            <property name="javax.persistence.logging.session" value="false"/>
            <property name="javax.persistence.logging.timestamp" value="false"/>
            <property name="javax.persistence.logging.exceptions" value="false"/>

            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/test?useUnicode=true&amp;characterEncoding=utf8"/>
            <property name="javax.persistence.jdbc.user" value="root"/>
            <property name="javax.persistence.jdbc.password" value="password"/>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
        </properties>
    </persistence-unit>
</persistence>

项目目录树：

$ tree
.
├── build
│   └── classes
│       ├── client
│       │   └── Client.class
│       ├── entity
│       │   ├── Customer.class
│       │   └── Order.class
│       └── META-INF
│           └── persistence.xml
├── sql
│   ├── tables_derby.sql
│   └── tables_oracle.sql
└── src
    ├── client
    │   └── Client.java
    ├── entity
    │   ├── Customer.java
    │   └── Order.java
    └── META-INF
        └── persistence.xml

10 directories, 10 files

所有clives代码与示例文件相同可在 http://glassfish.dev.java.net/javaee5/persistence/JPASE .zip

All clases code is identical to example file avaible at http://glassfish.dev.java.net/javaee5/persistence/JPASE.zip

推荐答案

persistence.xml 中缺少下一行：

<exclude-unlisted-classes>false</exclude-unlisted-classes>

此行放置在以下示例中：

This line is placed as in the following example:

<?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="SamplePU" transaction-type="RESOURCE_LOCAL">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <exclude-unlisted-classes>false</exclude-unlisted-classes>
    <properties>
      <property name="javax.persistence.jdbc.url" value="jdbc:derby://localhost:1527/sample"/>
      <property name="javax.persistence.jdbc.password" value="123"/>
      <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.ClientDriver"/>
      <property name="javax.persistence.jdbc.user" value="root"/>
      <property name="eclipselink.logging.level" value="ALL"/>
      <property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
    </properties>
  </persistence-unit>
</persistence>

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