Eclipse：持久性单元中未定义名为“system-uuid”的生成器
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Eclipse: No generator named "system-uuid" is defined in the persistence unit
提问by cmdematos
I have a maven enabled project imported into Eclipse. From Eclipse, I get an error "No generator named "system-uuid" is defined in the persistence unit" on the system-uuid portion of the following lines:
我有一个已启用 Maven 的项目导入到 Eclipse 中。在 Eclipse 中，我在以下几行的 system-uuid 部分收到错误“没有在持久性单元中定义名为“system-uuid”的生成器”：
@Id @GeneratedValue(generator = "system-uuid")
@GenericGenerator(name = "system-uuid", strategy = "uuid")
@Column(length = 36)
public String getId() {
return id;
}
The project builds correctly from the command line. What is causing Eclipse to generate this error and how do I fix it?
该项目从命令行正确构建。是什么导致 Eclipse 生成此错误，我该如何解决？
The persistence file looks like this..
持久性文件看起来像这样..
<persistence 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_1_0.xsd"
version="1.0">
<persistence-unit name="xxxx"/>
</persistence>
回答by Karen Butzke
You can turn the error off/down under Preferences -> Java Persistence -> JPA -> Errors/Warnings under 'Queries and Generators' by changing the error 'Generator is not defined in the persistence unit' to a warning.
您可以在“查询和生成器”下的“首选项”->“Java 持久性”->“JPA”->“错误/警告”下关闭/关闭错误，方法是将“生成器未在持久性单元中定义”错误更改为警告。
This looks like a bug in the Hibernate Tools extension of Dali in Eclipse.You could report this to Hibernate Tools or maybe this is fixed in a more recent version.
这看起来像是 Eclipse 中 Dali 的 Hibernate Tools 扩展中的一个错误。您可以将此报告给 Hibernate Tools，或者这可能会在更新的版本中得到修复。
回答by jeff
Eclipse Luna: This seems to work
Eclipse Luna：这似乎有效
Project -> Clean
回答by roehrijn
Newer versions of Eclipse' JPA support seem to depend on the order of Annotations. You are defining the generator after you try to use em.
较新版本的 Eclipse 的 JPA 支持似乎取决于注释的顺序。在尝试使用 em 之后，您正在定义生成器。
This will work:
这将起作用：
@Id
@GenericGenerator(name = "system-uuid", strategy = "uuid")
@GeneratedValue(generator = "system-uuid")
@Column(length = 36)
public String getId() {
return id;
}
However the order of annotations in Java must not have a meaning. So Karen is right, it seems to be a bug.
然而，Java 中的注解顺序一定没有意义。所以Karen是对的，这似乎是一个错误。
回答by Saadane Othmane
I had almost same error - I used my custom id generator - in eclipse mars after importing my project from github.
从 github 导入我的项目后，我在 eclipse mars 中遇到了几乎相同的错误 - 我使用了我的自定义 id 生成器。
the error : No generator named “idGenEchantillon” is defined in the persistence unit
错误： 持久性单元中未定义名为“idGenEchantillon”的生成器
So my answer is not really for the main question, but for other developers having same error as mine which can see here.
所以我的答案并不是真正针对主要问题，而是针对与我的错误相同的其他开发人员，可以在这里看到。
the code :
编码 ：
@Id
@GenericGenerator(name = "idGenEchantillon", strategy = "com.labo.model.KeyGenaratorForEchantillon")
@GeneratedValue(generator ="idGenEchantillon")
@Column(name = "ID_ECHANTILLON", length = 12)
private String idEchantillon;
I used maven to manage dependencies.
我使用 maven 来管理依赖项。
- I've removed the JPA facet from my project => every time I update my prject using Maven, the project take the JPA facet again => the error stay.
- I've disabled "JPA Configurator" option of Maven : Window >> Preferences >> Maven >> Java EE Integration , then uncheck "JPA CONFIGURATOR", after that I've update my project using Maven => the error is gone.
- 我已经从我的项目中删除了 JPA 方面 => 每次我使用 Maven 更新我的项目时，项目都会再次采用 JPA 方面 => 错误仍然存在。
- 我已禁用 Maven 的“JPA Configurator”选项：Window >> Preferences >> Maven >> Java EE Integration，然后取消选中“JPA CONFIGURATOR”，之后我使用 Maven 更新了我的项目 => 错误消失了。
