尝试卸载 NetBeans 12.0 时出现 NullPointerException答案

【问题标题】：NullPointerException when trying to uninstall NetBeans 12.0尝试卸载 NetBeans 12.0 时出现 NullPointerException
【发布时间】：2020-08-11 12:12:05
【问题描述】：

我正在尝试卸载 NetBeans 12.0，但向导在启动时抛出以下异常：

Exception: java.lang.NullPointerException: null

日志是这样说的：

[2020-08-11 14:03:20.249]:     initializing product registry properties
[2020-08-11 14:03:20.249]:     exiting -- org.netbeans.installer.product.Registry.initializeRegistry():170
[2020-08-11 14:03:20.253]:     ... loading registry from file:/C:/Users/Kai/.nbi/registry.xml
[2020-08-11 14:03:20.311]:     entering -- org.netbeans.installer.product.Registry.loadProductRegistry():981
[2020-08-11 14:03:20.312]:     validating previous installations
[2020-08-11 14:03:20.378]:         NameResolver - to parse C:\Program Files\NetBeans 8.2
[2020-08-11 14:03:20.392]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.396]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.404]:         NameResolver - to parse C:\Program Files\NetBeans 8.2\bin\jre
[2020-08-11 14:03:20.407]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.410]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.414]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.417]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.424]:         NameResolver - to parse C:\Program Files\NetBeans 8.2
[2020-08-11 14:03:20.425]:     ... validating installations finished
[2020-08-11 14:03:20.425]:     exiting -- org.netbeans.installer.product.Registry.loadProductRegistry():981
[2020-08-11 14:03:20.425]:     ... loading registry from resource:data/registry.xml
[2020-08-11 14:03:20.434]:     entering -- org.netbeans.installer.product.Registry.loadProductRegistry():981
[2020-08-11 14:03:20.434]:     validating previous installations
[2020-08-11 14:03:20.434]:         NameResolver - to parse C:\Program Files\NetBeans 8.2
[2020-08-11 14:03:20.435]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.437]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.437]:         NameResolver - to parse C:\Program Files\NetBeans 8.2\bin\jre
[2020-08-11 14:03:20.438]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.439]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.440]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.441]:         NameResolver - to parse C:\Program Files\NetBeans-12.0
[2020-08-11 14:03:20.442]:         NameResolver - to parse C:\Program Files\NetBeans 8.2
[2020-08-11 14:03:20.443]:     ... validating installations finished
[2020-08-11 14:03:20.443]:     exiting -- org.netbeans.installer.product.Registry.loadProductRegistry():981
[2020-08-11 14:03:20.447]:     An unexpected exception happened in thread Thread-2
[2020-08-11 14:03:20.448]:     java.lang.NullPointerException
[2020-08-11 14:03:20.448]:      at org.netbeans.installer.utils.helper.Version.equals(Version.java:69)
[2020-08-11 14:03:20.448]:      at org.netbeans.installer.product.Registry.changeStatuses(Registry.java:600)
[2020-08-11 14:03:20.448]:      at org.netbeans.installer.product.Registry.initializeRegistry(Registry.java:184)
[2020-08-11 14:03:20.448]:      at org.netbeans.installer.wizard.components.actions.InitializeRegistryAction.execute(InitializeRegistryAction.java:53)
[2020-08-11 14:03:20.448]:      at org.netbeans.installer.wizard.components.actions.netbeans.NbInitializationAction.execute(NbInitializationAction.java:69)
[2020-08-11 14:03:20.448]:      at org.netbeans.installer.wizard.components.WizardAction$1.run(WizardAction.java:103)
[2020-08-11 14:03:20.448]:     ... show message dialog
[2020-08-11 14:03:20.448]:         title: Critical Error
[2020-08-11 14:03:20.448]:         message: An unexpected exception happened in thread Thread-2
[2020-08-11 14:03:20.449]:         
[2020-08-11 14:03:20.449]:         Exception:
[2020-08-11 14:03:20.449]:           java.lang.NullPointerException:
[2020-08-11 14:03:20.449]:           null
[2020-08-11 14:03:20.449]:         
[2020-08-11 14:03:20.449]:         You can get more details about the issue in the installer log file:
[2020-08-11 14:03:20.449]:          C:\Users\Kai\.nbi\log\20200811140318.log
[2020-08-11 14:03:27.074]:     ... dialog closed

有谁知道如何修复此错误或使用其他方法卸载 NetBeans 12.0？

【问题讨论】：

[1] 安装NB12.0时使用的是什么版本的Java，卸载时使用的是什么版本？ [2] 不幸的是，由于您已删除 .nbi 目录，因此为时已晚，但日志中已明确说明了进行此操作的适当方法：You can get more details about the issue in the installer log file: [2020-08-11 14:03:20.449]: C:\Users\Kai\.nbi\log\20200811140318.log
[1] 我使用 AdoptOpen JDK 11 进行开发。 [2] 我在这篇文章中发布了日志文件的相关部分，但我无法弄清楚问题所在。

标签： netbeans netbeans-12

【解决方案1】：

经过反复试验，以下方法对我有用：

进入您的用户目录 (C:\Users\YourUsername\) 并在其中找到 .nbi 目录
删除 .nbi 目录（或将其移至其他位置）
运行 NetBeans 12.0 卸载程序

之后，卸载向导找不到 NetBeans 12.0 的注册表项并停止卸载过程。为了解决这个问题，我做了以下事情：

删除您的 Netbeans 12.0 目录 (C:\Programs\NetBeans 12.0\)
使用安装向导再次安装 NetBeans 12.0
通过 Windows 10 设置卸载 NetBeans 12.0

最后，我能够卸载 NetBeans 12.0 而没有出现 Nullpointer 异常。

【讨论】：