sudo aptitude install yui-compressor

cat *.js > original.js
yui-compressor -type js -o compressed.js original.js

cat *.css > original.css
yui-compressor -type css -o compressed.css original.css

<path id="yuicompressor.classpath">
   <fileset dir="${yuicompressor.dir}">
         <include name="**/yuicompressor-2.2.5.jar"/>
         <include name="**/YUIAnt.jar"/>
         <!– include name="**/rhino*.jar"/ –>
   </fileset>
</path> 
 
<target name="js.compress">
    <taskdef name="yuicompress" classname="com.yahoo.platform.yui.compressor.YUICompressTask">
       <classpath>
          <path refid="yuicompressor.classpath"/>
       </classpath>
    </taskdef>
 
    <yuicompress warn="false" munge="yes" preserveallsemicolons="true" outputfolder="${js-min.dir}" >
        <fileset dir="${js.dir}" >
            <include name="javascript/*.js" />
          </fileset>
      </yuicompress>
</target>

<project>
...
  <build>
    <plugins>
...
      <plugin>
        <groupId>net.alchim31.maven</groupId>
        <artifactId>yuicompressor-maven-plugin</artifactId>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>compress</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
            <failOnWarning>true</failOnWarning>
            <nosuffix>true</nosuffix>
             <force>true</force>
             <aggregations>
                 <aggregation>
                      <!-- Elimina los archivos declarado en agregations (default: false) -->
                      <removeIncluded>false</removeIncluded>
 
                      <!-- Inserta una linea despues de concatenar los archivos (default: false) -->
                      <insertNewLine>false</insertNewLine>
 
                      <!-- Es el archivo generado a partir de comprimir cada JS -->
                      <output>${project.basedir}/${webcontent.dir}/js/compressed.js</output>
 
                      <!-- Los archivos JS que deben comprimirse -->
                      <includes>                
                          <include>javascript/*.js</include>
                      </includes>
 
                      <!-- Los archivos JS que deben omitirse -->
                      <excludes>
	                 <exclude>...</exclude>
                      </excludes>
                 </aggregation>
             </aggregations>
          </configuration>
      </plugin>
...
    </plugins>
  </build>
...
</project>