osgi包已解决，但在运行时给出异常，不支持主。次版本51.0

Question

我对在现有的Tomcat中添加我自己的包感兴趣。因此，我在另一台机器上开发并测试了一个样例包，该包具有Java1.7和所选编译器的兼容性为1.6，该包在其他机器上运行良好。当我部署包时，它有一个解析状态，但是当我尝试启动包时，它抛出“unsupported major.minor version 51”。

更新：很明显，我部署了一个仍然在Java1.7中编译的包的旧版本，我重新编译了一个兼容1.6的包，现在包是活动的。

    osgi> ss sample

    Framework is launched.

    id      State       Bundle
    77      RESOLVED    sample.http2_1.0.0.2

    osgi> start 77
    org.osgi.framework.BundleException: The activator sample.http2.Activator for bundle sample.http2 is invalid
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadBundleActivator(AbstractBundle.java:157)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:750)
    at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:352)
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:280)
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:272)
    at org.eclipse.osgi.framework.internal.core.FrameworkCommandProvider._start(FrameworkCommandProvider.java:253)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.eclipse.osgi.framework.internal.core.FrameworkCommandInterpreter.execute(FrameworkCommandInterpreter.java:155)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.docommand(FrameworkConsole.java:303)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.console(FrameworkConsole.java:288)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.run(FrameworkConsole.java:224)
    at java.lang.Thread.run(Thread.java:619)
    Caused by: java.lang.UnsupportedClassVersionError: sample/http2/Activator : Unsupported major.minor version 51.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
    at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.defineClass(DefaultClassLoader.java:183)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.defineClass(ClasspathManager.java:576)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findClassImpl(ClasspathManager.java:546)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClassImpl(ClasspathManager.java:477)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClass_LockClassLoader(ClasspathManager.java:465)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClass(ClasspathManager.java:445)
    at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.findLocalClass(DefaultClassLoader.java:211)
    at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(BundleLoader.java:376)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:452)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:405)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:393)
    at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:105)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
    at org.eclipse.osgi.internal.loader.BundleLoader.loadClass(BundleLoader.java:321)
    at org.eclipse.osgi.framework.internal.core.BundleHost.loadClass(BundleHost.java:231)
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadBundleActivator(AbstractBundle.java:150)
    ... 14 more
    Nested Exception:
    java.lang.UnsupportedClassVersionError: sample/http2/Activator : Unsupported major.minor version 51.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
    at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.defineClass(DefaultClassLoader.java:183)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.defineClass(ClasspathManager.java:576)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findClassImpl(ClasspathManager.java:546)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClassImpl(ClasspathManager.java:477)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClass_LockClassLoader(ClasspathManager.java:465)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClass(ClasspathManager.java:445)
    at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.findLocalClass(DefaultClassLoader.java:211)
    at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(BundleLoader.java:376)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:452)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:405)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:393)
    at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:105)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
    at org.eclipse.osgi.internal.loader.BundleLoader.loadClass(BundleLoader.java:321)
    at org.eclipse.osgi.framework.internal.core.BundleHost.loadClass(BundleHost.java:231)
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadBundleActivator(AbstractBundle.java:150)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:750)
    at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:352)
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:280)
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:272)
    at org.eclipse.osgi.framework.internal.core.FrameworkCommandProvider._start(FrameworkCommandProvider.java:253)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.eclipse.osgi.framework.internal.core.FrameworkCommandInterpreter.execute(FrameworkCommandInterpreter.java:155)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.docommand(FrameworkConsole.java:303)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.console(FrameworkConsole.java:288)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.run(FrameworkConsole.java:224)
    at java.lang.Thread.run(Thread.java:619)
    Nested Exception:
    java.lang.UnsupportedClassVersionError: sample/http2/Activator : Unsupported major.minor version 51.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
    at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.defineClass(DefaultClassLoader.java:183)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.defineClass(ClasspathManager.java:576)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findClassImpl(ClasspathManager.java:546)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClassImpl(ClasspathManager.java:477)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClass_LockClassLoader(ClasspathManager.java:465)
    at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClass(ClasspathManager.java:445)
    at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.findLocalClass(DefaultClassLoader.java:211)
    at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(BundleLoader.java:376)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:452)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:405)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:393)
    at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:105)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
    at org.eclipse.osgi.internal.loader.BundleLoader.loadClass(BundleLoader.java:321)
    at org.eclipse.osgi.framework.internal.core.BundleHost.loadClass(BundleHost.java:231)
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadBundleActivator(AbstractBundle.java:150)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:750)
    at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:352)
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:280)
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:272)
    at org.eclipse.osgi.framework.internal.core.FrameworkCommandProvider._start(FrameworkCommandProvider.java:253)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.eclipse.osgi.framework.internal.core.FrameworkCommandInterpreter.execute(FrameworkCommandInterpreter.java:155)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.docommand(FrameworkConsole.java:303)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.console(FrameworkConsole.java:288)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.run(FrameworkConsole.java:224)
    at java.lang.Thread.run(Thread.java:619)

    osgi>       

Answer 1

您的类文件是为Java7(Version=51)编译的，但您（可能）在Java6(Version=50)上运行它，参见维基百科。

所以它只是VM在一个未知的类文件面前犹豫不决。请注意，Java有不同的兼容性设置。有Java源级兼容性和Java目标兼容性。类格式文件版本由目标兼容性设置，请参见另一个stackoverflow问题。在javac中，您希望指定-target1.6。

当您使用OSGi中的OSGi Bundle-RequiredExecutionEnvironment选项时，您可以在启动应用程序之前得到一个更易读的错误。