我想在Apache Karaf上运行的OSGi捆绑包中使用xbean配置创建嵌入式ActiveMQ代理。此代码：
brokerService = BrokerFactory.createBroker("xbean:file:etc/config.xml");
失败，出现以下异常：
org.springframework.beans.factory.BeanDefinitionStoreException: Failed to load type: org.apache.activemq.xbean.XBeanBrokerService. Reason: java.lang.ClassNotFoundException: org.apache.activemq.xbean.XBeanBrokerService not found by org.apache.xbean.spring [81]; nested exception is java.lang.ClassNotFoundException: org.apache.activemq.xbean.XBeanBrokerService not found by org.apache.xbean.spring [81]
at org.apache.xbean.spring.context.v2c.XBeanQNameHelper.getBeanInfo(XBeanQNameHelper.java:75)
at org.apache.xbean.spring.context.v2c.XBeanQNameHelper.coerceNamespaceAwarePropertyValues(XBeanQNameHelper.java:54)
at org.apache.xbean.spring.context.v2c.XBeanBeanDefinitionParserDelegate.parseBeanDefinitionElement(XBeanBeanDefinitionParserDelegate.java:59)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseBeanDefinitionElement(BeanDefinitionParserDelegate.java:396)
at org.apache.xbean.spring.context.v2c.XBeanNamespaceHandler.parseBeanFromExtensionElement(XBeanNamespaceHandler.java:224)
at org.apache.xbean.spring.context.v2c.XBeanNamespaceHandler.parseBeanFromExtensionElement(XBeanNamespaceHandler.java:276)
at org.apache.xbean.spring.context.v2c.XBeanNamespaceHandler.parse(XBeanNamespaceHandler.java:156)
at org.apache.xbean.spring.context.v2.XBeanNamespaceHandler.parse(XBeanNamespaceHandler.java:49)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1338)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1328)
at org.apache.xbean.spring.context.v2.XBeanBeanDefinitionDocumentReader.parseBeanDefinitions(XBeanBeanDefinitionDocumentReader.java:84)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.registerBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:93)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registerBeanDefinitions(XmlBeanDefinitionReader.java:493)
at org.apache.xbean.spring.context.v2.XBeanXmlBeanDefinitionReader.registerBeanDefinitions(XBeanXmlBeanDefinitionReader.java:79)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:390)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:334)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:302)
at org.apache.xbean.spring.context.ResourceXmlApplicationContext.loadBeanDefinitions(ResourceXmlApplicationContext.java:111)
at org.apache.xbean.spring.context.ResourceXmlApplicationContext.loadBeanDefinitions(ResourceXmlApplicationContext.java:104)
at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:130)
at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:467)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:397)
at org.apache.xbean.spring.context.ResourceXmlApplicationContext.<init>(ResourceXmlApplicationContext.java:64)
at org.apache.xbean.spring.context.ResourceXmlApplicationContext.<init>(ResourceXmlApplicationContext.java:52)
at org.apache.activemq.xbean.XBeanBrokerFactory$1.<init>(XBeanBrokerFactory.java:114)
at org.apache.activemq.xbean.XBeanBrokerFactory.createApplicationContext(XBeanBrokerFactory.java:114)
at org.apache.activemq.xbean.XBeanBrokerFactory.createBroker(XBeanBrokerFactory.java:70)
at org.apache.activemq.broker.BrokerFactory.createBroker(BrokerFactory.java:71)
at org.apache.activemq.broker.BrokerFactory.createBroker(BrokerFactory.java:54)
at org.apache.activemq.broker.BrokerFactory.createBroker(BrokerFactory.java:85)
at jmstest.bundle.TestActivator.start(TestActivator.java:18)
at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:629)
at org.apache.felix.framework.Felix.activateBundle(Felix.java:1842)
at org.apache.felix.framework.Felix.startBundle(Felix.java:1759)
at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1163)
at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:264)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.ClassNotFoundException: org.apache.activemq.xbean.XBeanBrokerService not found by org.apache.xbean.spring [81]
at org.apache.felix.framework.ModuleImpl.findClassOrResourceByDelegation(ModuleImpl.java:787)
at org.apache.felix.framework.ModuleImpl.access$400(ModuleImpl.java:71)
at org.apache.felix.framework.ModuleImpl$ModuleClassLoader.loadClass(ModuleImpl.java:1768)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at org.apache.xbean.spring.context.v2c.XBeanQNameHelper.loadClass(XBeanQNameHelper.java:107)
at org.apache.xbean.spring.context.v2c.XBeanQNameHelper.getBeanInfo(XBeanQNameHelper.java:72)
... 36 more
所有需要的捆绑包（activemq，activemq-spring，xbean-spring）都已加载并运行，我的捆绑包将它们全部Import-Package。
从独立的 ActiveMQ 代理加载的相同配置文件可以正常工作。
我相信这种情况正在发生，因为 xbean 无法访问它不导入的捆绑包中的类。有没有办法解决这个问题？
我自己解决了这个问题，但它看起来像一个黑客。如果有人告诉如何使它成为可能，请表示感谢。
这个想法是用加载当前类的类加载器替换默认类加载器（在我的例子中是捆绑激活器）：
ClassLoader c = Thread.currentThread().getContextClassLoader();
Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
brokerService = BrokerFactory.createBroker("xbean:file:etc/config.xml");
brokerService.start();
Thread.currentThread().setContextClassLoader(c);
XBean 在加载类时会尝试多个类加载器，包括线程上下文类加载器。当然，getClass().getClassLoader()加载器知道我的捆绑包的导入，因此 XBean 设法加载所有需要的类（前提是它们在 Import-Package 标头中）。也许这对其他人也有帮助。