Sorry to say that life is never so easy my friend:).....
Doing so would just enable the maven plugin for your project.You need to do the rest by your self.
Basically ensure you project structure is in the below structure as this is the standard structure for a maven project.
my-app
|-- pom.xml
`-- src
|-- main
| |-- java
| | `-- com
| | `-- mycompany
| | `-- app
| | `-- App.java
| `-- resources
| `-- META-INF
| `-- application.properties
`-- test
`-- java
`-- com
`-- mycompany
`-- app
`-- AppTest.java
copy all your java packages into src/main/java.
Then add your dependencies in pom.xml
Then you need to run maven clean install command to build the final jar into target folder.
I would like to suggest you to give a good reading about this .Below is the link.
http://maven.apache.org/guides/getting-started/index.html