Including dependencies in a jar with Maven

To include dependencies in a JAR file with Maven, you can use the maven-assembly-plugin to create an assembly that includes all the dependencies of your project.

First, add the maven-assembly-plugin to your pom.xml file and configure it to use an external descriptor:

<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-assembly-plugin</artifactId>
      <version>3.6.0</version>
      <configuration>
        <descriptors>
          <descriptor>src/main/assembly/assembly.xml</descriptor>
        </descriptors>
      </configuration>
    </plugin>
  </plugins>
</build>

Next, create the src/main/assembly/assembly.xml file to define how dependencies should be packaged:

<!-- src/main/assembly/assembly.xml -->
<assembly xmlns="http://maven.apache.org/ASSEMBLY/2.0.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/ASSEMBLY/2.0.0 http://maven.apache.org/xsd/assembly-2.0.0.xsd">
  <id>project</id>
  <formats>
    <format>jar</format>
  </formats>
  <includeBaseDirectory>false</includeBaseDirectory>
  <dependencySets>
    <dependencySet>
      <outputDirectory>/</outputDirectory>
      <useProjectArtifact>true</useProjectArtifact>
      <unpack>true</unpack>
    </dependencySet>
  </dependencySets>
</assembly>

Finally, run the assembly:single goal of the maven-assembly-plugin to create the JAR file with dependencies:

mvn assembly:single

This will create the JAR file in the target directory (typically named project-with-dependencies-project.jar based on your <finalName> and the <id> in the assembly descriptor), which includes all the dependencies of your project.

Note that assembly:single processes the current project. If you need to bundle dependencies for multiple modules or prefer better dependency conflict resolution, consider using the maven-shade-plugin instead.

To make the resulting JAR executable, ensure your pom.xml specifies the main class in the maven-jar-plugin configuration, or use the maven-shade-plugin to automatically set the Main-Class manifest attribute.