Hibernate配置不会列出XML中的所有实体

问题描述

目前在我的 hibernate.cfg.xml 文件中，我必须列出每个单独的实体作为映射类，以便我的Hibernate选取实体，否则我得到一个错误，如引用一个未知实体。

所以我有大约20个这样的行：

 < mapping class =my.com.entity.User>< / mapping> 
< mapping class =my.com.entity.Address>< / mapping> 
 ... 
  

不必每次都在XML文件中添加新行一个新的实体被创建，有没有办法告诉Hibernate嘿，只需从my.com.entity包中取出所有的东西作为一个实体？

解决方案

没有。即使使用最后一个Hibernate 5版本，你也不能说Hibernate会扫描持久化类的包。

使用Spring

使用Spring的常见方式如@Srini所示。

 < bean id =sessionFactoryclass =org.springframework.orm.hibernate5.LocalSessionFactoryBean> 
< property name =packagesToScan> 
< list> 
<值> my.com.entities< /值> 
<值> my.com.other.entities< /值> 
< / list> 
< / property> 
< / bean> 
  

请注意，取决于Hibernate版本，您需要使用包： org.springframework .orm.hibernate5 ， org.springframework.orm.hibernate4 。

使用流利hibernate

如果您不想使用Spring ，你可以使用
库（你不需要有其他的jar，除了库）。除此之外，它还具有Hibernate 5和Hibernate 4的一些有用功能，包括实体扫描，Hibernate 5隐式命名策略，嵌套转换器等。

对于Hibernate 4和Hibernate 5：

  Configuration configuration = new Configuration（）; 
 EntityScanner.scanPackages（my.com.entities，my.com.other.entities）
 .addTo（配置）; 
 SessionFactory sessionFactory = configuration.buildSessionFactory（）; 
  

使用新的Hibernate 5引导API：

  List< Class<？>> classes = EntityScanner 
 .scanPackages（my.com.entities，my.com.other.entities）。result（）; 
 
 MetadataSources metadataSources = new MetadataSources（）; （Class<> annotatedClass：classes）{
 metadataSources.addAnnotatedClass（annotatedClass）; 
; 
 
 
 SessionFactory sessionFactory = metadataSources.buildMetadata（）
 .buildSessionFactory（）; 
  

使用其他库

如果您已经使用可用于扫描的库，例如，那里是一个测试项目，其中包含使用各种库进行实体扫描的示例： hibernate-scanners-test 一>。

Currently in my hibernate.cfg.xml file, I have to list each individual entity as a mapping class in order for my Hibernate to pick up the Entity or else I get an error like references an unknown entity.

So I have about 20 of these lines:

<mapping class="my.com.entity.User"></mapping>
<mapping class="my.com.entity.Address"></mapping>
...

Instead of having to put a new line in the XML file each time a new Entity is created, is there a way to tell Hibernate "Hey, just pull in everything from the my.com.entity package as a Entity"?

解决方案

No. You can't say Hibernate to scan packages for persistent classes even with the last Hibernate 5 version.

Using Spring

The common way to use Spring for that, as @Srini suggested.

<bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
  <property name="packagesToScan">
    <list>
      <value>my.com.entities</value>
      <value>my.com.other.entities</value>
    </list>
  </property>
</bean>

Note that depends of Hibernate version you need to use package: org.springframework.orm.hibernate5, org.springframework.orm.hibernate4.

Using fluent-hibernate

If you don't want to use Spring, you can useEntityScanner from fluent-hibernate library (you will not need to have other jars, except the library). Apart this, it has some useful features for Hibernate 5 and Hibernate 4, including entities scanning, a Hibernate 5 implicit naming strategy, a nested transformer and others.

For Hibernate 4 and Hibernate 5:

Configuration configuration = new Configuration();
EntityScanner.scanPackages("my.com.entities", "my.com.other.entities")
    .addTo(configuration);
SessionFactory sessionFactory = configuration.buildSessionFactory();

Using a new Hibernate 5 bootstrapping API:

List<Class<?>> classes = EntityScanner
        .scanPackages("my.com.entities", "my.com.other.entities").result();

MetadataSources metadataSources = new MetadataSources();
for (Class<?> annotatedClass : classes) {
    metadataSources.addAnnotatedClass(annotatedClass);
}

SessionFactory sessionFactory = metadataSources.buildMetadata()
    .buildSessionFactory();

Using other libraries

If you already use a library that can be used for scanning, for an example Reflections, there is a test project with examples of using various libraries for entity scanning: hibernate-scanners-test.

这篇关于Hibernate配置不会列出XML中的所有实体的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！