Provisioning Api using Java

Question

Hello I tried one application which is used to store First 100 users in my domain to the table using JPA.But its returning Server Error. Pealse Help me. This is the code i tried..

         public class AppsProvisioning {
       public String m[]=new String[1000];
  public int a;
  final EntityManager em = EMFService.get().createEntityManager();
//public static void main(String[] args)
 public void calluser() throws AppsForYourDomainException, ServiceException,    
  {

  try {

    // Create a new Apps Provisioning service
    UserService myService = new UserService("My Application");
    myService.setUserCredentials("[email protected]","xxxxxxxx");

    // Get a list of all entries
    URL metafeedUrl = new URL("https://www.google.com/a/feeds/domain/user/2.0/");
    System.out.println("Getting user entries...\n");
    UserFeed resultFeed = myService.getFeed(metafeedUrl, UserFeed.class);
    List<UserEntry> entries = resultFeed.getEntries();
    for(int i=0; i<entries.size(); i++) {

      UserEntry entry = entries.get(i);
      m[i]=entry.getTitle().getPlainText();
      table greeting1 = new table(m[i]);
      em.persist(greeting1);
      System.out.println("\t" + entry.getTitle().getPlainText());
    }


    a=entries.size();
    System.out.println("\nTotal Entries: "+entries.size());
    }


  catch(AuthenticationException e) {
    e.printStackTrace();
  }
  catch(MalformedURLException e) {
    e.printStackTrace();
  }
  catch(ServiceException e) {
    e.printStackTrace();
  }
  catch(IOException e) {
    e.printStackTrace();
  }
  finally
  {    
   em.close();
  }
}

}

I think error in em.close() Error is:Server Error The server encountered an error and could not complete your request. Regards Sharun