Maven null dependency and multiple annotations on this line

Question

Something has gone wrong with my pom and I have a blank dependency and artifactId in the xml but get the same error whether I delete the tags or not.

I am using eclipse with m2eclipse installed in my home folder on Linux Mint 14 with maven version 'Apache Maven 2.2.1 (rdebian-8)' installed

Here is the pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>TransferHandler</groupId>
  <artifactId>TransferHandler</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <build>
    <sourceDirectory>src</sourceDirectory>
    <testSourceDirectory>test</testSourceDirectory>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>2.3.2</version>
        <configuration>
          <source>1.7</source>
          <target>1.7</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
  <dependencies>
    <dependency>
        <groupId>com.sun.mail</groupId>
        <artifactId>javax.mail</artifactId>
        <version>1.4.6-rc1</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.11</version>
    </dependency>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-vfs2</artifactId>
        <version>2.0</version>
    </dependency>
    <dependency>
        <groupId>commons-logging</groupId>
        <artifactId>commons-logging</artifactId>
        <version>1.1.1</version>
    </dependency>
    <dependency>
        <groupId>com.jcraft</groupId>
        <artifactId>jsch</artifactId>
        <version>0.1.49</version>
    </dependency>
    <dependency>
        <groupId>commons-net</groupId>
        <artifactId>commons-net</artifactId>
        <version>3.2</version>
        <classifier>ftp</classifier>
    </dependency>
    <dependency>
        <groupId>commons-httpclient</groupId>
        <artifactId>commons-httpclient</artifactId>
        <version>3.1</version>
    </dependency>
    <dependency>
        <groupId>commons-collections</groupId>
        <artifactId>commons-collections</artifactId>
        <version>3.2.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-io</artifactId>
        <version>1.3.2</version>
    </dependency>
    <dependency>
        <artifactId></artifactId>
    </dependency>
  </dependencies>
</project>

There are three error messages displayed:

On line1:

Multiple annotations found at this line: - null (org.apache.maven.plugins:maven-resources-plugin:2.5:resources:default-resources:process-resources) - null (org.apache.maven.plugins:maven-resources-plugin:2.5:testResources:default-testResources:process-test- resources)

On line70:

Multiple annotations found at this line: - Project build error: 'dependencies.dependency.groupId' for null::jar is missing. - Project build error: 'dependencies.dependency.version' for null::jar is missing.

On line 71:

Project build error: 'dependencies.dependency.artifactId' for null::jar is missing.

It seems like the one on line 70 with the empty tags is the root cause (excerpt below) but I'm not sure.

<dependency>
        <artifactId></artifactId>
</dependency>

Even if I delete the empty tags from the xml and refresh maven and the project the error remains. On my Dependencies tab I see a jar with a '?' next to it but can't delete it and in my Dependency Hierachy tab I see a ' : [compile]' jar but can delete or exclude it.

How can I remove this ghost/null jar?

You need to update your project and not only refresh the configuration. The problem is in Eclipse which needs to be reloaded which can be done by clicking on the project -> Maven -> Update Project. — khmarbaise, Feb 06 '13 at 15:26
Thanks khmar, I tried that too but errors are still there and the '?' jar is still under dependencies — eljaydub, Feb 06 '13 at 15:49

Don Ramos · Answer 1 · 2013-02-06T13:36:12.723

0

Try This Header

<project xmlns="http://maven.apache.org/POM/4.0.0"         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

Good Luck !

edited Feb 06 '13 at 13:36

answered Feb 06 '13 at 13:30

Don Ramos

1
1

Thanks Don but that didn't work either; I still get the error: Multiple annotations found at this line: - null (org.apache.maven.plugins:maven-resources-plugin:2.5:resources:default-resources:process-resources) - null (org.apache.maven.plugins:maven-resources-plugin:2.5:testResources:default-testResources:process-test- resources) on that line as well as the other errors – eljaydub Feb 06 '13 at 14:59
Try to run mvn -U install from command line and then "Maven->Update Project" from Eclipse – Don Ramos Feb 06 '13 at 16:16

score 0 · Accepted Answer · answered Feb 06 '13 at 16:05

I found a way around the problem using git but was not able to solve it directly by removing the offending packages. The work-around was to shutdown eclipse, remove the pom and then use git to discard changes in the working directory. Commands:

 rm pom.xml
 git checkout -- pom.xml

Then the pom should reappear returned to its state at the last commit (which luckily for me was before this error arose). Not a very satisfying answer but at least it worked. If anyone posts an answer and explanation to the heart of the real problem (ie why can't I remove a null package and how did it get there in the first place) I would still be happy to accept it.

Maven null dependency and multiple annotations on this line

2 Answers2