我正在尝试从Modular Java book中运行该示例并面临ClassNotFoundException。错误的要点是我有2个捆绑。
捆绑1称为索引。 Bundle 2是Compass项目的包装捆绑包。
Bundle 1使用Bundle 2，并在其清单中的“Import-Package”标头中声明了Bundle 2中使用的包。 Bundle 2也会导出相同的包。
Index（Bundle 1）使用的Bundle 2的类，调用Bundle 2内部的几个类。这些类的包也由Bundle 2导出。但每当我在Felix（使用Pax-runner）上部署它们时，启动失败并出现以下错误。
[FelixDispatchQueue] DEBUG main-findmyjar.index - BundleEvent STOPPED - main-findmyjar.index
ERROR: Bundle main-findmyjar.index [7] Error starting file:bundles/main-findmyjar.index_1.0.0.SNAPSHOT.jar (org.osgi.framework.BundleException: Activator start error in bundle main-findmyjar.index [7].)
org.compass.core.config.ConfigurationException: Failed to instantiate [org.compass.core.config.binding.metadata.AsmMetaDataReader], please verify class type at setting [compass.scanner.reader]; nested exception is java.lang.ClassNotFoundException: org.compass.core.config.binding.metadata.AsmMetaDataReader
java.lang.ClassNotFoundException: org.compass.core.config.binding.metadata.AsmMetaDataReader
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:247)
at org.compass.core.util.ClassUtils.forName(ClassUtils.java:90)
at org.compass.core.config.CompassSettings.getSettingAsInstance(CompassSettings.java:304)
at org.compass.core.config.binding.metadata.MetaDataReaderFactory.getMetaDataReader(MetaDataReaderFactory.java:35)
at org.compass.core.config.binding.AbstractClassMetaDataMappingBinding.setUpBinding(AbstractClassMetaDataMappingBinding.java:24)
at org.compass.annotations.config.binding.AnnotationsMappingBinding.setUpBinding(AnnotationsMappingBinding.java:93)
at org.compass.core.config.CompassMappingBinding.setUpBinding(CompassMappingBinding.java:56)
at org.compass.core.config.CompassConfiguration.getMappingBinding(CompassConfiguration.java:121)
at org.compass.core.config.CompassConfiguration.addClass(CompassConfiguration.java:500)
at org.gt.osgi.findmyjar.index.internal.Activator.getCompass(Activator.java:40)
at org.gt.osgi.findmyjar.index.internal.Activator.start(Activator.java:35)
at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:645)
at org.apache.felix.framework.Felix.activateBundle(Felix.java:1977)
at org.apache.felix.framework.Felix.startBundle(Felix.java:1895)
at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1191)
at org.apache.felix.framework.FrameworkStartLevelImpl.run(FrameworkStartLevelImpl.java:295)
at java.lang.Thread.run(Thread.java:662)
[FelixDispatchQueue] DEBUG main-findmyjar.index - FrameworkEvent ERROR - main-findmyjar.index
org.osgi.framework.BundleException: Activator start error in bundle main-findmyjar.index [7].
at org.apache.felix.framework.Felix.activateBundle(Felix.java:2027)
at org.apache.felix.framework.Felix.startBundle(Felix.java:1895)
at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1191)
at org.apache.felix.framework.FrameworkStartLevelImpl.run(FrameworkStartLevelImpl.java:295)
at java.lang.Thread.run(Thread.java:662)
Caused by: org.compass.core.config.ConfigurationException: Failed to instantiate [org.compass.core.config.binding.metadata.AsmMetaDataReader], please verify class type at setting [compass.scanner.reader]; nested exception is java.lang.ClassNotFoundException: org.compass.core.config.binding.metadata.AsmMetaDataReader
at org.compass.core.config.CompassSettings.getSettingAsInstance(CompassSettings.java:306)
at org.compass.core.config.binding.metadata.MetaDataReaderFactory.getMetaDataReader(MetaDataReaderFactory.java:35)
at org.compass.core.config.binding.AbstractClassMetaDataMappingBinding.setUpBinding(AbstractClassMetaDataMappingBinding.java:24)
at org.compass.annotations.config.binding.AnnotationsMappingBinding.setUpBinding(AnnotationsMappingBinding.java:93)
at org.compass.core.config.CompassMappingBinding.setUpBinding(CompassMappingBinding.java:56)
at org.compass.core.config.CompassConfiguration.getMappingBinding(CompassConfiguration.java:121)
at org.compass.core.config.CompassConfiguration.addClass(CompassConfiguration.java:500)
at org.gt.osgi.findmyjar.index.internal.Activator.getCompass(Activator.java:40)
at org.gt.osgi.findmyjar.index.internal.Activator.start(Activator.java:35)
at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:645)
at org.apache.felix.framework.Felix.activateBundle(Felix.java:1977)
... 4 more
Caused by: java.lang.ClassNotFoundException: org.compass.core.config.binding.metadata.AsmMetaDataReader
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:247)
at org.compass.core.util.ClassUtils.forName(ClassUtils.java:90)
at org.compass.core.config.CompassSettings.getSettingAsInstance(CompassSettings.java:304)
... 14 more
[FelixDispatchQueue] DEBUG org.apache.felix.framework - BundleEvent STARTED - org.apache.felix.framework
[FelixDispatchQueue] DEBUG org.apache.felix.framework - FrameworkEvent STARTED - org.apache.felix.framework
可能出现什么问题的线索？
这是清单。
Manifest-Version: 1.0
Export-Package: org.gt.osgi.findmyjar.index;uses:="org.gt.osgi.findmyj
ar.domain";version="1.0.0.SNAPSHOT"
Private-Package: org.gt.osgi.findmyjar.index.internal
Ignore-Package: org.gt.osgi.findmyjar.index.internal
Built-By: tyagig
Tool: Bnd-0.0.255
Bundle-Name: main-findmyjar.index
Created-By: Apache Maven Bundle Plugin
Build-Jdk: 1.6.0_32
Bundle-Version: 1.0.0.SNAPSHOT
Bnd-LastModified: 1357910690482
Bundle-ManifestVersion: 2
Bundle-Activator: org.gt.osgi.findmyjar.index.internal.Activator
Bundle-Description: Generated using Pax-Construct
Bundle-SymbolicName: main-findmyjar.index
Import-Package: org.compass.core,org.compass.core.config,org.compass.c
ore.config.binding.metadata,org.gt.osgi.findmyjar.domain;version="1.0
.0.SNAPSHOT",org.gt.osgi.findmyjar.index;version="1.0.0.SNAPSHOT",org
.osgi.framework
答案 0 :(得分：3)
好像你有一个org.compass.core.util.ClassUtils，它有一个Class.forName（），它可以解决这个问题。
如果ClassUtils在bundle 2中并且没有给出使用的显式类加载器，它将默认为bundle classloader。 bundleclassloader只能实例化bundle2可见的类（在整个类图中）。
它尝试加载的设置很可能是在bundle1中指定的类，它是不可见的。
解决方法是在动态加载类或查看类加载器的gerying机制时将类加载器从bundle1传递到bundle2。有一个旧的article可能会更清楚地解释这一点。