Java 获得；无法创建目录"；Maven JAXB插件中出错，但只有一次

在我的Maven构建中，我使用

jaxb2 Maven插件：2.2

从XML模式文件生成类。这些是项目中唯一的Java文件，即没有未生成的Java文件

当我使用干净的项目运行

mvn compile

时，我遇到以下错误：

[ERROR] Failed to execute goal org.codehaus.mojo:jaxb2-maven-plugin:2.2:xjc (xjc) on project awap: Unable to create directory D:\myproject\target\classes\ -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:jaxb2-maven-plugin:2.2:xjc (xjc) on project awap: Unable to create directory D:\myproject\target\classes\
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    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)
    at org.codehaus.classworlds.Launcher.main(Launcher.java:47)
Caused by: org.apache.maven.plugin.MojoExecutionException: Unable to create directory D:\myproject\target\classes\
    at org.codehaus.mojo.jaxb2.javageneration.AbstractJavaGeneratorMojo.performExecution(AbstractJavaGeneratorMojo.java:482)
    at org.codehaus.mojo.jaxb2.AbstractJaxbMojo.execute(AbstractJaxbMojo.java:257)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
    ... 21 more
Caused by: java.io.IOException: Unable to create directory D:\myproject\target\classes\
    at org.codehaus.plexus.util.FileUtils.forceMkdir(FileUtils.java:1615)
    at org.codehaus.mojo.jaxb2.javageneration.AbstractJavaGeneratorMojo.performExecution(AbstractJavaGeneratorMojo.java:439)
    ... 24 more

但是运行此操作后，

target/classes

目录确实存在！事实上，如果我再次尝试

mvn编译

（中间没有清理），构建就会成功

最新的插件版本2.4也会出现同样的错误

查看引发异常的函数的名称，我看到调用了

File.mkdirs（）

。我不知道为什么会返回

false

。毕竟，目录确实是在某个时候创建的

---

为什么会发生这种情况？我如何才能使我的构建在第一次成功？

因此我可以间接地解决这个问题。我在maven中将类生成到的（非标准）目录标记为源目录

我对此进行了更改，以便将类生成到默认的

target/generated sources

，并删除了额外的source文件夹。这使错误消失了