title: can maven compile multiple source folder to multiple target folder
body: <p>I am trying to change a ant project to maven project, here is the problem.
  for example: I have two source folder.</p>
  
  <pre><code>-pom.xml    
  -ejb
      -org
          -x
            -ejbclass1.java
  -tpf
      -org
          -x
            -tpfclass1.java
  </code></pre>
  
  <p>now I want to generate class file under target folder like this:</p>
  
  <pre><code>ejb
     -classes
             -org
                 -x
                   -ejbclass1.class
  tpf
     -classes
             -org
                 -x
                   -tpfclass1.class
  </code></pre>
  
  <p>is there any plugin can do this?</p>