The maven-dependency-plugin is a Maven plugin that analyze the dependencies. It works +/- the same way deco works. It scan the byte code of the classes to find which jar is required and which is not. This plugin has however currently some limitations (handling of runtime annotation is not suported, interfaces are not always reported properly, pedigree of the exceptions are not taken into account...).
Deco provides an alternate analyzer that can replace the default one.
To use it, you must declare your plugin like this:
<build>
...
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.2</version>
<configuration>
<analyzer>deco</analyzer>
</configuration>
<dependencies>
<dependency>
<artifactId>deco</artifactId>
<groupId>net.sourceforge.deco</groupId>
<version>0.3</version>
</dependency>
</dependencies>
</plugin>
...
</build>