使用Maven構建Liferay項目時出現NullPointerException

Question

我正在使用Maven而不是Ant創建Liferay插件。

問題是，在某些開發環境中，當我嘗試運行mvn clean package時遇到以下異常：

[DEBUG] Trace
org.apache.maven.lifecycle.LifecycleExecutionException
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:719)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalWithLifecycle(DefaultLifecycleExecutor.java:556)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:535)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:387)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:348)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:180)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
    at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
    at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
    at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
    at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
Caused by: org.apache.maven.plugin.MojoExecutionException
    at com.liferay.maven.plugins.AbstractLiferayMojo.execute(AbstractLiferayMojo.java:88)
    at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:694)
    ... 17 more
Caused by: java.lang.NullPointerException
    at com.liferay.maven.plugins.AbstractLiferayMojo.getProjectClassPath(AbstractLiferayMojo.java:268)
    at com.liferay.maven.plugins.AbstractLiferayMojo.getProjectClassLoader(AbstractLiferayMojo.java:255)
    at com.liferay.maven.plugins.SassToCssBuilderMojo.doExecute(SassToCssBuilderMojo.java:90)
    at com.liferay.maven.plugins.AbstractLiferayMojo.execute(AbstractLiferayMojo.java:81)
    ... 19 more

我已經有了這個問題的答案，我只是添加這個問題以分享知識。 我在任何地方都找不到此錯誤。

Answer 1

該錯誤與插件本身無關，而與Maven的版本有關。 當您嘗試使用舊版本的Maven構建Liferay項目時，將引發該錯誤。

當我們將Maven更新到v3.0.5時，出現錯誤並且項目正在正確構建。

Answer 2

您是否嘗試過跑步：

清潔包裝liferay：部署