M2eclipse java. Lang. nullpointerexception

An error is reported when you use m2eclipse to import an existing Maven project.

 

Java. Lang. nullpointerexception
At org. Apache. Maven. plugin. defaultindescriptorcache $ cachekey. <init> (defaultplugindescriptorcache. Java: 165)
At org. Apache. Maven. plugin. defaultindescriptorcache. createkey (defaultplugindescriptorcache. Java: 62)
At org. Apache. Maven. plugin. Internal. defaultmavenpluginmanager. getplugindescriptor (defaultmavenpluginmanager. Java: 136)
At org. Apache. Maven. plugin. Internal. defaultmavenpluginmanager. getmojodescriptor (defaultmavenpluginmanager. Java: 261)
At org. Apache. Maven. plugin. defaultbuildpluginmanager. getmojodescriptor (defabuilbuildpluginmanager. Java: 192)
At org. Maven. Ide. Eclipse. Internal. embedder. mavenimpl. getmojoparametervalue (mavenimpl. Java: 765)
At org. Maven. Ide. Eclipse. jdt. Internal. abstractjavaprojectconfigurator. addprojectsourcefolders (abstractjavaprojectconfigurator. Java: 248)
At org. Maven. Ide. Eclipse. jdt. Internal. abstractjavaprojectconfigurator. Configure (abstractjavaprojectconfigurator. Java: 99)
At org. Maven. Ide. Eclipse. Project. configurator. abstractlifecyclemapping. Configure (abstractlifecyclemapping. Java: 57)
At org. Maven. Ide. Eclipse. Internal. Project. genericlifecyclemapping. Configure (genericlifecyclemapping. Java: 48)
At org. Maven. Ide. Eclipse. Internal. Project. projectconfigurationmanager. updateprojectconfiguration (projectconfigurationmanager. Java: 306)
At org. Maven. Ide. Eclipse. Internal. Project. projectconfigurationmanager. configurenewmavenproject (projectconfigurationmanager. Java: 240)
At org. Maven. Ide. Eclipse. Internal. Project. projectconfigurationmanager. enablemavennature (projectconfigurationmanager. Java: 317)
At org. Maven. Ide. Eclipse. Actions. enablenatureaction $ 1.run( enablenatureaction. Java: 123)
At org.eclipse.core.internal.jobs. Worker. Run (worker. Java: 54)

 

 

The reason is that the plug-in POM. XML does not have a specific version.

 

For example

No version is specified for the plug-in that caused the above error.

<Plugin>
<Groupid> org. Apache. Maven. plugins </groupid>
<Artifactid> Maven-compiler-plugin </artifactid>
</Plugin>

 

Correct syntax:

<Plugin>
<Groupid> org. Apache. Maven. plugins </groupid>
<Artifactid> Maven-compiler-plugin </artifactid>
<Version> 2.3.2 </version> <! -- Note that you need to write the version number -->
</Plugin>

 

 

Source

Https://bugs.eclipse.org/bugs/show_bug.cgi? Id = 340285