java - 无法构建 Java Netbeans 项目

Question

几天前，我在构建该项目时没有遇到任何问题。但突然我无法访问lib目录(SchoolManagement/SchoolManagement/dist/lib)。我什至无法删除 lib 目录。它显示错误“访问被拒绝!”。

输出日志显示:

    ant -f C:\\Users\\Dinesh\\Dropbox\\SchoolManagement\\SchoolManagement -   Dnb.internal.action.name=rebuild clean jar
    init:
    deps-clean:
    Deleting directory    C:\Users\Dinesh\Dropbox\SchoolManagement\SchoolManagement\build
    clean:
    init:
    deps-jar:
    Created dir: C:\Users\Dinesh\Dropbox\SchoolManagement\SchoolManagement\build\classes
    Created dir: C:\Users\Dinesh\Dropbox\SchoolManagement\SchoolManagement\build\empty
    Created dir: C:\Users\Dinesh\Dropbox\SchoolManagement\SchoolManagement\build\generated-sources\ap-source-output
    Compiling 14 source files to C:\Users\Dinesh\Dropbox\SchoolManagement\SchoolManagement\build\classes
    Note: Some input files use or override a deprecated API.
    Note: Recompile with -Xlint:deprecation for details.
    Note: Some input files use unchecked or unsafe operations.
    Note: Recompile with -Xlint:unchecked for details.
    Copying 2 files to C:\Users\Dinesh\Dropbox\SchoolManagement\SchoolManagement\build\classes
compile:
    Copying 1 file to C:\Users\Dinesh\Dropbox\SchoolManagement\SchoolManagement\build
    Copy libraries to C:\Users\Dinesh\Dropbox\SchoolManagement\SchoolManagement\dist\lib.
C:\Users\Dinesh\Dropbox\SchoolManagement\SchoolManagement\nbproject\build-impl.xml:993: The following error occurred while executing this line:
C:\Users\Dinesh\Dropbox\SchoolManagement\SchoolManagement\nbproject\build-impl.xml:837: 
java.lang.NullPointerException
    at org.apache.tools.ant.util.ResourceUtils.copyResource(ResourceUtils.java:439)
    at org.apache.tools.ant.util.FileUtils.copyFile(FileUtils.java:559)
    at org.apache.tools.ant.util.FileUtils.copyFile(FileUtils.java:519)
    at org.apache.tools.ant.util.FileUtils.copyFile(FileUtils.java:480)
    at org.apache.tools.ant.util.FileUtils.copyFile(FileUtils.java:443)
    at org.apache.tools.ant.util.FileUtils.copyFile(FileUtils.java:409)
    at org.apache.tools.ant.util.FileUtils.copyFile(FileUtils.java:384)
    at org.apache.tools.ant.util.FileUtils.copyFile(FileUtils.java:322)
    at org.netbeans.modules.java.j2seproject.copylibstask.CopyLibs.execute(CopyLibs.java:206)
    at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
    at sun.reflect.GeneratedMethodAccessor103.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
    at org.apache.tools.ant.Task.perform(Task.java:348)
    at org.apache.tools.ant.taskdefs.Sequential.execute(Sequential.java:68)
    at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
    at sun.reflect.GeneratedMethodAccessor103.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
    at org.apache.tools.ant.Task.perform(Task.java:348)
    at org.apache.tools.ant.taskdefs.MacroInstance.execute(MacroInstance.java:396)
    at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
    at sun.reflect.GeneratedMethodAccessor103.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
    at org.apache.tools.ant.Task.perform(Task.java:348)
    at org.apache.tools.ant.Target.execute(Target.java:435)
    at org.apache.tools.ant.Target.performTasks(Target.java:456)
    at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1393)
    at org.apache.tools.ant.Project.executeTarget(Project.java:1364)
    at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
    at org.apache.tools.ant.Project.executeTargets(Project.java:1248)
    at org.apache.tools.ant.module.bridge.impl.BridgeImpl.run(BridgeImpl.java:286)
    at org.apache.tools.ant.module.run.TargetExecutor.run(TargetExecutor.java:555)
    at org.netbeans.core.execution.RunClassThread.run(RunClassThread.java:153)
BUILD FAILED (total time: 28 seconds)

Answer 1

好的，首先我们可能需要查看确切的代码行，以防万一出现空指针错误，但这可能是由于无法访问您的目录，具体取决于您的 Netbeans 对 C:/驱动器的权限。

可能的解决方案

如果 Netbeans 无法删除该目录，您可能需要尝试以管理员身份运行 netbeans 以获得所需的权限(右键单击并以管理员身份运行)，然后也许它会起作用。另外似乎存在空指针异常，但这可能是因为缺乏权限

其他解决方案

由于这是一个学校项目，如果您在学校计算机上运行，​​我会在某种程度上假设他们可能为您提供了一个没有提升权限的帐户，这可能是问题所在，您可以尝试手动将文件复制到您的帐户具有读/写权限的新位置。