PermGen error

 
import com.google.gwt.user.client.rpc.IsSerializable;
 
public class PersonDTO implements IsSerializable
{
    private int id = 0;
    private String firstname = null;
    private String lastname = null;
 
    /**
     * @return the firstname
     */
     public String getFirstname()
     {
         return firstname;
     }
 
    /**
     * @param firstname the firstname to set
     */
     public void setFirstname(String firstname)
     {
         this.firstname = firstname;
     }
 
     /**
      * @return the lastname
      */
      public String getLastname()
      {
          return lastname;
      }
 
     /**
      * @param lastname the lastname to set
      */
      public void setLastname(String lastname)
      {
          this.lastname = lastname;
      }
 
     /**
      * @return the id
      */
      public int getId()
      {
          return id;
      }
 
     /**
      * @param id the id to set
      */
      public void setId(int id)
      {
          this.id = id;
      }
}

import com.google.gwt.user.client.ui.MultiWordSuggestOracle.MultiWordSuggestion;
 
/**
 * @author James Heggs - jheggs@axonbirch.com
 *
 */
public class PersonMultiWordSuggestion extends MultiWordSuggestion
{
    private PersonDTO personDTO = null;
 
    public PersonMultiWordSuggestion(PersonDTO user)
    {
        super(user.getFirstname() + " " + user.getLastname(), 
              user.getFirstname() + " " + user.getLastname() );
 
        this.personDTO = user;
    }
 
 
    /**
     * @return the personDTO
     */
     public PersonDTO getPersonDTO()
     {
         return personDTO;
     }
}

 
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
 
import com.google.gwt.user.client.ui.SuggestOracle;
 
/**
 * @author James Heggs - jheggs@axonbirch.com
 *
 */
public class PersonNameSuggestOracle extends SuggestOracle
{
    private List<PersonMultiWordSuggestion> personSuggestions = null;
 
    @Override
    public void requestSuggestions(Request request, Callback callback)
    {
        Response resp = new Response( matchingPeople( request.getQuery(),
                                                      request.getLimit() ) );
 
        callback.onSuggestionsReady(request, resp);
    }
 
    /**
     * 
     * @param query The current text being entered into the suggest box
     * @param limit The maximum number of results to return 
     * @return A collection of people suggestions that match.
     */
     public Collection<PersonMultiWordSuggestion> matchingPeople(String query, int limit)
     {
         List<PersonMultiWordSuggestion> matchingPeople = new ArrayList<PersonMultiWordSuggestion>(limit);
 
         // only begin to search after the user has type two characters
         if ( query.length() >= 2 )
         {
             String prefixToMatch = query.toLowerCase();
 
             int i = 0;
             int s = personSuggestions.size();
 
             // Skip forward over all the names that don't match at the beginning of the array.
             while (i < s && !personSuggestions.get(i).getDisplayString().toLowerCase().startsWith(prefixToMatch) )
             {
                 i++;
             }
 
             // Now we are at the start of the block of matching names. Add matching names till we
             // run out of names, stop finding matches, or have enough matches.
             int count = 0;
 
             while (i < s && personSuggestions.get(i).getDisplayString().toLowerCase().startsWith(prefixToMatch) && count < limit) 
             {
                 matchingPeople.add( personSuggestions.get(i) );
                 i++;
                 count++;
             }
 
         }
 
             return matchingPeople;
     }
 
 
 
        /**
         * @param o 
         * @return
         * @see java.util.List#add(java.lang.Object)
         */
         public boolean add(PersonMultiWordSuggestion o)
         {
             if ( personSuggestions == null )
             {
                personSuggestions = new ArrayList<PersonMultiWordSuggestion>();
             }
 
             return personSuggestions.add(o);
         }
 
 
 
        /**
         * @param o
         * @return
         * @see java.util.List#remove(java.lang.Object)
         */
         public boolean remove(Object o)
         {
             if ( personSuggestions != null)
             {
                 return personSuggestions.remove(o);
             }
 
             return false;
          }
 
}

 
PersonNameSuggestOracle oracle = new PersonNameSuggestOracle();
SuggestBox nameSuggestBox = new SuggestBox(oracle);
 
 
//fetch names
  MyServiceAsync serviceRPC = GWT.create(MyService.class);
  serviceRPC.fetchPeople(new AsyncCallback< List<PersonDTO> >()
  {
   public void onFailure(Throwable caught)
   {
    // TODO Auto-generated method stub
 
   }
 
   public void onSuccess(List<PersonDTO> results)
   {
    if ( results != null && results.size() > 0 )
    {
     for ( PersonDTO person : results )
     {
      oracle.add(new PersonMultiWordSuggestion(person) );
     }
    }
 
   }
  });

nameSuggestBox.addEventHandler(new SuggestionHandler()
{
    public void onSuggestionSelected(SuggestionEvent event)
    {
        PersonMultiWordSuggestion suggestion = (PersonMultiWordSuggestion)event.getSelectedSuggestion();
 
        // Do what you want with the suggestion and DTO
        // suggestion.getPersonDTO
 
 
    }
});