Maven assembly plugin support Jar format? - maven-2

Question

I have configured my assembly descriptor to have an assembly of type jar by
<formats>
<format>jar</format>
</formats>
However,on running mvn install getting zip files instead of jar.Where I have gone wrong?

Answer 1

This configuration produces a jar assembly with the classifier jar-assembly containing only the contents of target/classes. You can add additional filesets if needed to add other content to the jar. To ensure you don't have zip archives from any previous runs in your target directory, you can delete it or run mvn clean.
<assembly>
<id>jar-assembly</id>
<formats>
<format>jar</format>
</formats>
<includeBaseDirectory>false</includeBaseDirectory>
<fileSets>
<fileSet>
<directory>${project.build.outputDirectory}</directory>
<outputDirectory>/</outputDirectory>
</fileSet>
</fileSets>
</assembly>
The plugin configuration should look something like this. Note setting appendAssemblyId to false will cause the default jar to be replaced by the jar from the assembly, remove that element if this is not the desired behaviour:
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.2-beta-2</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
<configuration>
<appendAssemblyId>false</appendAssemblyId>
<descriptors>
<descriptor>src/main/assembly/archive.xml</descriptor>
</descriptors>
</configuration>
</execution>
</executions>
</plugin>

Answer 2

Why don't you use the pre-defined assembly jar-with-dependencies? Below the descriptor file:
<assembly>
<id>jar-with-dependencies</id>
<formats>
<format>jar</format>
</formats>
<includeBaseDirectory>false</includeBaseDirectory>
<dependencySets>
<dependencySet>
<unpack>true</unpack>
<scope>runtime</scope>
</dependencySet>
</dependencySets>
<fileSets>
<fileSet>
<directory>${project.build.outputDirectory}</directory>
</fileSet>
</fileSets>
</assembly>
To use assembly:assembly using a predefined descriptor, run:
mvn assembly:assembly -DdescriptorId=jar-with-dependencies
To produce the assembly as part of the normal build cycle, bind the single or single-directory mojo to the package phase (see Usage):
<project>
[...]
<build>
[...]
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.2-beta-5</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id> <!-- this is used for inheritance merges -->
<phase>package</phase> <!-- append to the packaging phase. -->
<goals>
<goal>single</goal> <!-- goals == mojos -->
</goals>
</execution>
</executions>
</plugin>
[...]
</project>