Maven SNAPSHOT jar file names not consistent using Maven Assembly in MANIFEST file

Question

Here is the scenario:

Two Maven 3 project builds.

Build 1 has snapshot jars that get deployed to Nexus.

Build 2 has dependencies on the snapshots, referenced like 1.0.0-SNAPSHOT, that gets packaged up and zipped up using the mvn clean package assembly:single command.

The issue that we run into: Occasionally when the assembly is being created, the MANIFEST file for the jar will sometimes say some.jar.1.0.0-SNAPSHOT and sometimes it will say some.jar.1.0.0-datetime stamp, thus causing class not defined errors.

Is there a way to prevent this naming issue in the manifest file?

--edit--

Further research has discovered the following:

"If the snapshot was resolved from a repo then it will be timestamped, if it came from the reactor or local repo, then it will be -SNAPSHOT. The plugin calls into the maven resolution logic so this is core maven behavior. "

This is the exact issue that is being run into. The 2nd build manifest file always has an entry of ./lib/Framework-1.0.0-SNAPSHOT.jar where as the actual jar file name changes between ./lib/Framework-1.0.0-SNAPSHOT.jar and ./lib/Framework-1.0.0-timestamp.jar based on the quote above.

Answer 1

In <dependencySet> you need to set <outputFileNameMapping>${artifact.artifactId}-${artifact.baseVersion}.${artifact.extension}</outputFileNameMapping>

for example:

<assembly xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 http://maven.apache.org/xsd/assembly-1.1.2.xsd">
  <id>appserverB</id>
  <formats>
    <format>zip</format>
  </formats>
  <dependencySets>
    <dependencySet>
      <outputDirectory>/lib</outputDirectory>
      <outputFileNameMapping>${artifact.artifactId}-${artifact.baseVersion}.${artifact.extension}</outputFileNameMapping>
      <includes>
        <include>application:logging</include>
        <include>application:core</include>
        <include>application:utils</include>
        <include>application:appserverB</include>
      </includes>
    </dependencySet>
  </dependencySets>
</assembly>

If you are using one of the built-in assembly descriptors you will need to replicate it for your self and add in the outputFileNameMapping entry yourself

Answer 2

For people who use maven-jar-plugin to create the artifact which is then packed by the maven-assembly-plugin and you still see timestamps in the classpath in artifact names, you can disable that by setting useUniqueVersions=false, as follows:

<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>${maven-jar-plugin.version}</version>
<configuration>
    <archive>
        <manifest>
            <addClasspath>true</addClasspath>
            <classpathPrefix>${project.build.finalName}.lib/</classpathPrefix>
            <mainClass>com.nate.Application</mainClass>
            <!-- To force the use of '-SNAPSHOT' version naming, simply disable the <useUniqueVersions>  -->
            <useUniqueVersions>false</useUniqueVersions>
        </manifest>
        <manifestEntries>
            <buildTime>${maven.timestamp}</buildTime>
        </manifestEntries>
    </archive>
</configuration>