Creating JAR with Maven dependencies

Question

I want to use the Maven to generate the JAR with its dependencies in format .jar, the solutions I found are not valid.

The Eclipse has three forms of generate a executable JAR.

1. Extract required Libraries into gerenated JAR
2. Package required Libraries into generated JAR < I use that in Eclipse.
3. Copy required Libraries into a sub-Folder next to the generated JAR

And Maven has a form equivalent to Eclipse?

---

Using maven-jar-plugin

   <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>2.4</version>
            <configuration>
                <archive>
                    <manifest>
                        <mainClass>qualquer.que.seja.seu.pacote.ClasseMain</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>

Problem: This mode generates a JAR without format dependencies .jar.

---

Using maven-assemply-plugin

<plugin>
    <artifactId>maven-assembly-plugin</artifactId>
    <configuration>
        <archive>
            <manifest>
                <mainClass>qualquer.que.seja.seu.pacote.ClasseMain</mainClass>
            </manifest>
        </archive>
        <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef>
        </descriptorRefs>
    </configuration>
</plugin>

Problem: Generates a JAR with "extracted" dependencies out of format .jars.

Answer 1

There is also the Maven Shade Plugin that allows you to package the artifact in a super-jar, including its dependencies, and even rename the packages of some dependencies if you wish.

Take an example:

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>2.2</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
            <configuration>
              <transformers>
                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                  <mainClass>org.sonatype.haven.HavenCli</mainClass>
                </transformer>
              </transformers>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

Besides putting everything together in a single jar, which makes it very easy to distribute for download, for example, the Shade also allows renaming dependency packages, helping a lot in cases where there may be classpath conflicts, for example.

It is important to note that plugins Shade and Assembly are not direct competitors, although the two allow to pack the dependencies in a jar. When it comes to packaging, Assembly is more powerful, flexible and complicated. Shade has fewer features, but to create a Uber-jar it is more direct and simple.

Answer 2

Missed you set up as the maven-assembly-plugin shall be executed, that is to say, which Goal and in what phase of Maven as well. To package a jar with dependencies during the package, the configuration looks like this:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-assembly-plugin</artifactId>
    <version>2.4</version>
    <configuration>
        <archive>
            <manifest>
                <mainClass>qualquer.que.seja.seu.pacote.ClasseMain</mainClass>
            </manifest>
        </archive>
        <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef>
        </descriptorRefs>
    </configuration>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>attached</goal>
            </goals>
        </execution>
    </executions>
</plugin>