maven - 在 NetBeans 中获取意外异常

Question

我在 NetBeans 中为 org.netbeans.modules.maven.j2ee.J2eeActionsProvider 得到一个 ClassNotFoundException:

Annotation: while loading from BinaryFileMap@b19ad5{fo=MultiFileObject@b4e1e7[Projects/org-netbeans-modules-maven/war/Lookup/org-netbeans-modules-maven-j2ee-J2eeActionsProvider.instance]} while loading from BinaryFileMap@b19ad5{fo=MultiFileObject@b4e1e7[Projects/org-netbeans-modules-maven/war/Lookup/org-netbeans-modules-maven-j2ee-J2eeActionsProvider.instance]} Caused by: java.lang.ClassNotFoundException: org.netbeans.modules.maven.j2ee.J2eeActionsProvider starting from SystemClassLoader[474 modules] with possible defining loaders null and declared parents [org.netbeans.MainImpl$BootClassLoader@12c6ec2, ModuleCL@4e4a22[org.netbeans.api.annotations.common], ModuleCL@c7fc0e[org.openide.awt], ModuleCL@7c7efa[org.netbeans.api.progress], ModuleCL@5936cd[org.openide.dialogs], ModuleCL@575101[org.openide.nodes], ModuleCL@1a7eac9[org.openide.windows], ModuleCL@a5c529[org.netbeans.modules.editor.mimelookup], ModuleCL@1d36f2e[org.openide.text], ModuleCL@134e1cc[org.netbeans.swing.tabcontrol], ...458 more] at org.netbeans.ProxyClassLoader.loadClass(ProxyClassLoader.java:224) at org.netbeans.ModuleManager$SystemClassLoader.loadClass(ModuleManager.java:722) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) at org.netbeans.modules.projectapi.LazyLookupProviders.loadPSPInstance(LazyLookupProviders.java:174) at org.netbeans.modules.projectapi.LazyLookupProviders.access$000(LazyLookupProviders.java:73) at org.netbeans.modules.projectapi.LazyLookupProviders$1$1.beforeLookup(LazyLookupProviders.java:118) at org.openide.util.lookup.ProxyLookup.beforeLookup(ProxyLookup.java:209) at org.openide.util.lookup.ProxyLookup$R.myBeforeLookup(ProxyLookup.java:667) at org.openide.util.lookup.ProxyLookup$R.beforeLookup(ProxyLookup.java:689) at org.openide.util.lookup.ProxyLookup$R.myBeforeLookup(ProxyLookup.java:676) at org.openide.util.lookup.ProxyLookup$R.beforeLookup(ProxyLookup.java:689) at org.openide.util.lookup.ExcludingLookup$R.beforeLookup(ExcludingLookup.java:328) at org.openide.util.lookup.ProxyLookup$R.myBeforeLookup(ProxyLookup.java:676) at org.openide.util.lookup.ProxyLookup$R.computeResult(ProxyLookup.java:549) at org.openide.util.lookup.ProxyLookup$R.allInstances(ProxyLookup.java:509) at org.openide.util.lookup.ProxyLookup$R.allInstances(ProxyLookup.java:505) at org.openide.util.lookup.SimpleProxyLookup$ProxyResult.allInstances(SimpleProxyLookup.java:267) at org.openide.util.Lookup.lookupAll(Lookup.java:271) at org.netbeans.modules.maven.execute.ActionToGoalUtils.actionProviders(ActionToGoalUtils.java:120) at org.netbeans.modules.maven.ActionProviderImpl.getSupportedActions(ActionProviderImpl.java:179) at org.netbeans.modules.project.ui.ProjectsRootNode$BadgingNode.canDestroy(ProjectsRootNode.java:884) at org.netbeans.modules.openide.explorer.ExplorerActionsImpl.updateActions(ExplorerActionsImpl.java:258) at org.netbeans.modules.openide.explorer.ExplorerActionsImpl$ActionStateUpdater.run(ExplorerActionsImpl.java:798) at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1423) at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2033) Caused by: java.lang.ClassNotFoundException: org.netbeans.modules.maven.j2ee.J2eeActionsProvider at java.net.URLClassLoader$1.run(URLClassLoader.java:372) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:360) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) at org.netbeans.ProxyClassLoader.loadClass(ProxyClassLoader.java:222) ... 24 more while loading from BinaryFileMap@b19ad5{fo=MultiFileObject@b4e1e7[Projects/org-netbeans-modules-maven/war/Lookup/org-netbeans-modules-maven-j2ee-J2eeActionsProvider.instance]}

为什么我会收到此异常？

Answer 1

ClassNotFoundException 通常意味着您的安装出现问题。

在这种情况下，存在 org.netbeans.modules.maven.j2ee.J2eeActionsProvider 注册条目，但未找到关联的类(但通常两者都位于同一模块中，因此两者都应该存在或缺失)