spring - Equinox (OSGi) 和 JPA/Hibernate - 查找实体

Question

我正在尝试在 OSGi (Equinox) 环境中使用 Hibernate/Spring。如果我明确地将它指向 Persistence.xml 中的实体类，它会很好用:

    <class>com.es.t.eee.domain.StuffSource</class>
    <class>com.es.t.eee.domain.PostalAddress</class>

我想要的是让 Hibernate “找到”所有实体类，就像它在 OSGi 环境之外所做的那样。

Hibernate 正在寻找 @Entities 的正确包:

Searching mapped entities in jar/par: bundleresource://34/
WARN  27-07 15:30:24,235 (InputStreamZippedJarVisitor.java:doProcessElements:41):
Unable to find file (ignored): bundleresource://34/

看起来它应该可以工作，但是当它在 Bundle Jar 中查找 @Entities 时，会发生异常，我不知道为什么。我已经包含了 Hibernate 吐出的日志的重要部分。

有谁知道我做错了什么或这里的问题是什么？

我在用:

hibernate 核心 3.3.0.SP1

hibernate 注释 3.4.0.GA

Hibernate Commons 注释 3.1.0.GA

hibernate 实体管理器 3.4.0.GA

春分 3.4

Spring 动态模块 1.2.0

这里是 Hibernate 解析 Persistence.xml 的地方

INFO  27-07 15:30:24,110 (Version.java:<clinit>:15):
Hibernate Annotations 3.4.0.GA
INFO  27-07 15:30:24,110 (Environment.java:<clinit>:543):
Hibernate 3.3.0.SP1
INFO  27-07 15:30:24,110 (Environment.java:<clinit>:576):
hibernate.properties not found
INFO  27-07 15:30:24,126 (Environment.java:buildBytecodeProvider:709):
Bytecode provider name : javassist
INFO  27-07 15:30:24,126 (Environment.java:<clinit>:627):
using JDK 1.4 java.sql.Timestamp handling
INFO  27-07 15:30:24,157 (Version.java:<clinit>:14):
Hibernate Commons Annotations 3.1.0.GA
INFO  27-07 15:30:24,157 (Version.java:<clinit>:16):
Hibernate EntityManager 3.4.0.GA
DEBUG 27-07 15:30:24,219 (Ejb3Configuration.java:configure:312):
Processing PersistenceUnitInfo [
    name: unit.postgresql
    persistence provider classname: null
    classloader: BundleDelegatingClassLoader for [DatabaseObjects (DatabaseObjects)]
    Temporary classloader: org.springframework.instrument.classloading.SimpleThrowawayClassLoader@11b50a1
    excludeUnlistedClasses: true
    JTA datasource: null
    Non JTA datasource: com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 3, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 1000, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> 1012f6d821goxcok12zcw86|174f02c, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> org.postgresql.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1012f6d821goxcok12zcw86|174f02c, idleConnectionTestPeriod -> 0, initialPoolSize -> 5, jdbcUrl -> jdbc:postgresql://localhost:5432/test2, lastAcquisitionFailureDefaultUser -> null, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 100, maxStatements -> 100, maxStatementsPerConnection -> 0, minPoolSize -> 3, numHelperThreads -> 3, numThreadsAwaitingCheckoutDefaultUser -> 0, preferredTestQuery -> null, properties -> {user=******, password=******}, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false ]
    Transaction type: RESOURCE_LOCAL
    PU root URL: bundleresource://34/
    Jar files URLs []
    Managed classes names []
    Mapping files names []
    Properties [
        hibernate.default_batch_fetch_size: 500
        hibernate.cache.provider_class: net.sf.ehcache.hibernate.EhCacheProvider
        hibernate.dialect: org.hibernate.dialect.PostgreSQLDialect
        hibernate.max_fetch_depth: 5
        hibernate.query.factory_class: org.hibernate.hql.ast.ASTQueryTranslatorFactory
        hibernate.format_sql: false
        hibernate.jdbc.batch_size: 1000
        hibernate.use_outer_join: true
        hibernate.archive.autodetection: class
        hibernate.show_sql: false
        hibernate.bytecode.provider: cglib]

这是错误发生的地方，因为它试图找到实体:

DEBUG 27-07 15:30:24,235 (Ejb3Configuration.java:getDetectedArtifacts:562):
Detect class: true; detect hbm: false
DEBUG 27-07 15:30:24,235 (Ejb3Configuration.java:getDetectedArtifacts:562):
Detect class: true; detect hbm: false
DEBUG 27-07 15:30:24,235 (AbstractJarVisitor.java:unqualify:116):
Searching mapped entities in jar/par: bundleresource://34/
WARN  27-07 15:30:24,235 (InputStreamZippedJarVisitor.java:doProcessElements:41):
Unable to find file (ignored): bundleresource://34/
java.lang.NullPointerException: in is null
    at java.util.zip.ZipInputStream.<init>(Unknown Source)
    at java.util.jar.JarInputStream.<init>(Unknown Source)
    at java.util.jar.JarInputStream.<init>(Unknown Source)
    at org.hibernate.ejb.packaging.InputStreamZippedJarVisitor.doProcessElements(InputStreamZippedJarVisitor.java:37)
    at org.hibernate.ejb.packaging.AbstractJarVisitor.getMatchingEntries(AbstractJarVisitor.java:139)
    at org.hibernate.ejb.Ejb3Configuration.addScannedEntries(Ejb3Configuration.java:287)
    at org.hibernate.ejb.Ejb3Configuration.scanForClasses(Ejb3Configuration.java:614)
    at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:360)
    at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:131)
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:224)
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:291)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1369)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1335)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:473)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164)
    at org.springframework.beans.factory.support.AbstractBeanFactory.isSingleton(AbstractBeanFactory.java:366)
    at org.springframework.osgi.service.exporter.support.OsgiServiceFactoryBean.afterPropertiesSet(OsgiServiceFactoryBean.java:235)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1369)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1335)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:473)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:423)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:728)
    at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext.completeRefresh(AbstractDelegatedExecutionApplicationContext.java:288)
    at org.springframework.osgi.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor$CompleteRefreshTask.run(DependencyWaiterApplicationContextExecutor.java:145)
    at java.lang.Thread.run(Unknown Source)

Answer 1

本博客 shows how it can be handled使用 Spring 的动态模块。
根据该博客，您将在应用程序上下文中为 DAO 和服务 bean 创建 bean 定义。 DAO 引用了 hibernate sessionFactory bean:

<bean id="stuffDao" class="com.es.t.eee.domain.dao.StuffSourceDaoImpl">
  <property name="sessionFactory" ref="sessionFactory"/>
</bean>
<bean id="stuffService" 
  class="com.es.t.eee.domain.dao.StuffServiceImpl">
  <property name="stuffDao" ref="stuffDao"/>
</bean>

<bean id="stuffSource" 
  class="com.es.t.eee.domain.StuffSource" scope="prototype"/>

StuffSourceDaoImpl 将实现 store() 方法来持久化 StuffSource，它将 StuffSource 传递给 HibernateTemplate 以实际进行持久化。
为了避免必须定义 persistence.xml 文件或指定每个实体，您可以使用 AnnotationSessionFactoryBean 和通配符来包含包含您的实体的包中的所有类型(您可能想要设置 packagesToScan 属性，我已经没有尝试过，它可能会让你回到原来的问题):

<bean id="sessionFactory"
    class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
  <property name="hibernateProperties">
    <props>
      <!--etc-->
    </props>
  </property>
  <!-- set either one of these properties -->
  <property name="annotatedClasses">
    <list>
      <value>com.es.t.eee.domain.StuffSource</value>
      <value>com.es.t.eee.domain.PostalAddress</value>
    </list>
  </property>
  <property name="packagesToScan">
    <list>
      <value>com.es.t.eee.domain</value>
    </list>
  </property>
</bean>

要使用它，您将获得 BundleContext，从上下文中获取服务和 bean，然后照常进行:

String serviceName = StuffService .class.getName();
StuffService service = 
  (StuffService )context.getService(context.getServiceReference(serviceName));

String stuffName = StuffSource.class.getName();
StuffSource stuffSource = 
  (StuffSource) context.getService(context.getServiceReference(stuffName ));

//do whatever with StuffSource
...

service.store(stuffSource );

您可能还想看看这个 OSGi Alliance blog讨论了所涉及的一些问题。来自 OSGi 联盟博客:

Hibernate manipulates the classpath, and programs like that usually do not work well together with OSGi based systems. The reason is that in many systems the class visibility between modules is more or less unrestricted. In OSGi frameworks, the classpath is well defined and restricted. This gives us a lot of good features but it also gives us pain when we want to use a library that has aspirations to become a classloader when it grows up....

To work with Hibernate, you need a Session object. You can get a Session object from a SessionFactory. To get the the SessionFactory, you need to create it with a Configuration object. The Configuration object is created from a configuration XML file. By default, Hibernate loads this from the root of your JAR file, however, you can add classes manually to the configuration if so desired.