title: Deploying a Jersey webapp on Jboss AS 7
body: <p>Currently running some webapps on Jboss AS 4/5 and I am testing migration to jboss7. When I try to deploy a jersey based webapp on JBoss AS 7 (full profile with standalone-preview config file), I get:</p>
  
  <pre><code>org.jboss.as.server.deployment.DeploymentUnitProcessingException: Only one JAX-RS Application Class allowed.
  </code></pre>
  
  <p>I've done a bit of hunting around on it and found that RestEasy is the default JAX-RS implementation embedded into Application Server. Posts like <a href="http://community.jboss.org/message/579996" rel="noreferrer">http://community.jboss.org/message/579996</a> and <a href="https://issues.jboss.org/browse/JBAS-8830" rel="noreferrer">https://issues.jboss.org/browse/JBAS-8830</a>) mention that the RestEasy deployer takes over. </p>
  
  <p>In AS 6, it seems easier to remove the deployer whereas I have not seen any solutions for AS 7.</p>