Question

Maven配置失败了这条线只是破坏了我周五晚上仍然无法解决它。好吧，我是视觉工作室代码的忠实粉丝，所以我决定将vscode切换到eclipse进行java开发。但这不是问题，当我尝试添加外部java库时出现问题。我无法使用它，我只是得到类似Class-not-Found之类的错误。

嗯，这是我在vscode中的项目结构

   [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.7.0:compile (default-compile) on project in.blackpaper.topdf: Compilation failure

这是我在安装mvn插件时收到的错误消息。

 mvn clean install

[DEBUG] incrementalBuildHelper#beforeRebuildExecution
[INFO] Compiling 1 source file to E:\Documents\Java\in.blackpaper.topdf\target\classes
[DEBUG] incrementalBuildHelper#afterRebuildExecution
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.086 s
[INFO] Finished at: 2018-04-17T11:23:29+05:30
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.7.0:compile (default-compile) on project in.blackpaper.topdf: Compilation failure
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[ERROR]
[ERROR] -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.7.0:compile (default-compile) on project in.blackpaper.topdf: Compilation failure
No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?

    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:213)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:154)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:146)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:290)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:194)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (Unknown Source)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (Unknown Source)
    at java.lang.reflect.Method.invoke (Unknown Source)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:289)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:229)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:415)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:356)
Caused by: org.apache.maven.plugin.compiler.CompilationFailureException: Compilation failure
No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?

    at org.apache.maven.plugin.compiler.AbstractCompilerMojo.execute (AbstractCompilerMojo.java:1161)
    at org.apache.maven.plugin.compiler.CompilerMojo.execute (CompilerMojo.java:168)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:208)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:154)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:146)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:290)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:194)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (Unknown Source)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (Unknown Source)
    at java.lang.reflect.Method.invoke (Unknown Source)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:289)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:229)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:415)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:356)
[ERROR]
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

好吧，我也尝试用vscode开发人员来解决我的问题，但我仍然无法解决它。这是我在vscode-github

中提出的问题

vscode-java/issue#509

好吧，我的问题与之前提到的关于maven-plugins的问题不同，我尝试了所有可用的解决方案，但无法明白这一点。

提前致谢。

Answer 1

您正在使用的Java安装不是Java开发工具包（您可以通过查看this question来了解其中的差异。）

要解决您的问题，请下载并安装 JDK （例如来自here或来自here，具体取决于您喜欢的版本），如果您没有＆＃ 39;已经安装好了。安装和/或解压后（如果您使用linix，最好在init脚本中完成）：

export JAVA_HOME=<path_to_the_extracted_jdk_directory>

在Windows上，创建一个名为JAVA_HOME的环境变量，其值设置为安装目录的完整路径。

要验证Maven是否选择了正确的Java安装，您可以尝试

mvn -version

输出包括Maven看到的Java安装的行，例如：

...·Maven home：[maven之路]
Java版本：1.8.0_152，供应商：Oracle Corporation
Java home：/home/user/jdk/jdk1.8.0_152/jre
...

Answer 2

请检查终端，该过程将锁定。因此，应用程序文件仍在某处使用。因此，首先我们需要停止该过程，然后启动您的任务，它将会起作用。

Maven插件无法执行

2 个答案: