Maven: Packaging dependencies alongside project JAR?

Question

I'd like Maven to package a project alongside its run-time dependencies. I expect it to create a JAR file with the following manifest:

..... Main-Class : com.acme.MainClass Class-Path : lib/dependency1.jar lib/dependency2.jar ..... 

and create the following directory structure:

target |-- .... |-- my-project.jar |-- lib     |-- dependency1.jar     |-- dependency2.jar 

Meaning, I want the main JAR to exclude any dependencies and I want all transitive dependencies to get copied into a "lib" sub-directory. Any ideas?

Answer 1

I've like Maven to package a project with run-time dependencies.

This part is unclear (it's not exactly what you describe just after). My answer covers what you described.

I expect it to create a JAR file with the following manifest (...)

Configure the Maven Jar Plugin to do so (or more precisely, the Maven Archiver):

<project>   ...   <build>     <plugins>       <plugin>          <artifactId>maven-jar-plugin</artifactId>          <configuration>            <archive>              <manifest>                <addClasspath>true</addClasspath>                <classpathPrefix>lib/</classpathPrefix>                <mainClass>com.acme.MainClass</mainClass>              </manifest>            </archive>          </configuration>       </plugin>     </plugins>   </build>   ...   <dependencies>     <dependency>       <groupId>dependency1</groupId>       <artifactId>dependency1</artifactId>       <version>X.Y</version>     </dependency>     <dependency>       <groupId>dependency2</groupId>       <artifactId>dependency2</artifactId>       <version>W.Z</version>     </dependency>   </dependencies>   ... </project> 

And this will produce a MANIFEST.MF with the following entries:

... Main-Class: fully.qualified.MainClass Class-Path: lib/dependency1-X.Y.jar lib/dependency2-W.Z.jar ... 

and create the following directory structure (...)

This is doable using the Maven Dependency Plugin and the dependency:copy-dependencies goal. From the documentation:

• dependency:copy-dependencies takes the list of project direct dependencies and optionally transitive dependencies and copies them to a specified location, stripping the version if desired. This goal can also be run from the command line.

You could bind it on the package phase:

<project>   [...]   <build>     <plugins>       <plugin>         <groupId>org.apache.maven.plugins</groupId>         <artifactId>maven-dependency-plugin</artifactId>         <version>2.1</version>         <executions>           <execution>             <id>copy-dependencies</id>             <phase>package</phase>             <goals>               <goal>copy-dependencies</goal>             </goals>             <configuration>               <outputDirectory>${project.build.directory}/lib</outputDirectory>               <overWriteReleases>false</overWriteReleases>               <overWriteSnapshots>false</overWriteSnapshots>               <overWriteIfNewer>true</overWriteIfNewer>             </configuration>           </execution>         </executions>       </plugin>     </plugins>   </build>   [...] </project> 

Answer 2

Add the following plugins in pom.xml. Check the value at mainClass,classpathPrefix,addClasspath tags.

<plugin>         <groupId>org.apache.maven.plugins</groupId>         <artifactId>maven-jar-plugin</artifactId>         <version>2.4</version>         <configuration>             <archive>                 <manifest>                     <mainClass>org.apache.camel.spring.Main</mainClass>                     <classpathPrefix>lib/</classpathPrefix>                     <addClasspath>true</addClasspath>                 </manifest>             </archive>         </configuration>     </plugin>     <plugin>         <groupId>org.apache.maven.plugins</groupId>         <artifactId>maven-assembly-plugin</artifactId>         <version>2.4</version>         <configuration>             <descriptors>                 <descriptor>src/assembly/some-assembly.xml</descriptor>             </descriptors>         </configuration>         <executions>             <execution>                 <id>make-assembly</id>                 <phase>package</phase>                 <goals>                     <goal>single</goal>                 </goals>             </execution>         </executions>     </plugin> 

Create some-assembly.xml under src/assembly as below.

<assembly xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0 http://maven.apache.org/xsd/assembly-1.1.0.xsd"> <id>distribution</id> <formats>     <format>zip</format> </formats> <includeBaseDirectory>true</includeBaseDirectory> <fileSets>     <fileSet>         <directory>${project.build.directory}</directory>         <outputDirectory>/</outputDirectory>         <includes>             <include>*.jar</include>         </includes>     </fileSet> </fileSets> <dependencySets>     <dependencySet>         <scope>runtime</scope>         <outputDirectory>/lib</outputDirectory>         <useProjectArtifact>false</useProjectArtifact>         <unpack>false</unpack>     </dependencySet> </dependencySets> 

Note that useProjectArtifact flag to false, unpack flag to false. If root folder inside zip file is not required,then one can make includeBaseDirectory to false.

This will create name-version-distribution.zip file. Inside zip file, there will be folder name-version. Inside this folder, your executable jar and lib folder containing all dependency jars will be present. Check manifest.MF file of executable jar. It contains both main class and classpath information.