[FIXED] Maven Compile Access Denied Copying Dependencies

Issue

I have a weird problem with Maven that I've not run into before. I appear to be the only one having the problem on my team and this is for a project that has existed for a significant period of time (10+ years). I'm new to the team, but so are other members who do not seem to be having this problem.

Here's the problem:

If I do a mvn clean compile, I get the following error:

[ERROR] Failed to execute goal org.codehaus.mojo:dependency-maven-plugin:1.0:copy (copy-dependencies)
  on project deployable-war: Error copying artifact
  from C:\...\dependency\target\classes
  to C:\...\deployable-war\target\dependency\jws\lib\classes:
  C:\...\dependency\target\classes (Access is denied) -> [Help 1]

Now, the weird part is that source and destination folders (dependency\target\classes and deployable-war\target\dependency\jws\lib\classes) were both created by Maven during the same compile command. This is a multi-module project, so mvn compile will go through all 9 modules. This is module 8. The dependency module is module 7.

If I re-run mvn compile (without the clean) afterwards, it gives the same error, so it does not seem to be a timing issue.

If I manually create the folder (mkdir ...\deployable-war\target\dependency\jws\lib\classes) and re-run mvn compile, everything works fine. That includes it copying JAR files inside of the lib folder that it said was access denied when it tried to create the classes folder.

I've tried deleting the \target\ folder entirely.

I've tried running Maven as an administrator.

I've tried checking out a new copy of the project from Git into a new directory on my local.

I've checked folder permissions on the project itself to ensure that my user and the administrator user have full control.

OS is Windows 10 Enterprise.

Any suggestions?

EDIT: From discussion, tracked the error down to this part of the pom.xml for the module:

<build>
        <finalName>deployable</finalName>
        <plugins>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>dependency-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <id>copy-dependencies</id>
                        <phase>compile</phase>
                        <goals>
                            <goal>copy</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${project.build.directory}/${project.build.finalName}/jws/lib</outputDirectory>
                            <artifactItems>
                                <artifactItem>

Now, the issue appears to be related to a subset of the artifactItem - particular, artifactItems that do not have explicitly-defined destFileNames.

Solution

Long time coming back to this, but Gerold's comment lead me to the right resolution. The problem was the copy-dependencies happens after package. So the problem was that I was mvn clean compile, when I needed to be mvn clean package

I limped along taking way too long to sort that out. The fun of multi-module, interdependent projects

Answered By - Jeremy Smith