Hi Paul, Thanks for sharing this idea. I've added a link to it in a related RFE:
"Improve parameter validation" http://restlet.tigris.org/issues/show_bug.cgi?id=221 If you could contribute your class that would be nice. You just need to attach it to the RFE above and to take care of the JCA paperwork: http://www.restlet.org/community/contribute Best regards, Jerome Louvel -- Restlet ~ Founder and Lead developer ~ http://www.restlet.org Noelios Technologies ~ Co-founder ~ http://www.noelios.com -----Message d'origine----- De : Paul J. Lucas [mailto:[EMAIL PROTECTED] Envoye : jeudi 7 aout 2008 17:24 A : [email protected] Objet : Any interest in a DTO class? I wanted a simple way to get the values of request parameters into an Object. I've implemented a DTO (Data Transfer Object) class that can be used for this. Suppose you want to implement a query request. You could do something like: public class QueryDTO extends DTO { @Required public String q; public SortOrder order; // SortOrder is enum { NAME, DATE, SIZE } public Boolean desc; QueryDTO( Request request ) throws DTOException { super( request ); if ( order == null ) order == SortOrder.NAME; if ( desc == null ) desc = Boolean.FALSE; } } What this says is that a request has 3 query parameters. Of those, "q" is a required String. The DTO constructor takes care of all the parsing of form data (for both APPLICATION_WWW_FORM and MULTIPART_FORM_DATA cases), enforces @Require constraints, and handles enum values. You can then use it like: public void handleGet() { try { QueryDTO dto = new QueryDTO( getRequest() ); // ... use dto.{members} as you please ... } catch ( DTOException e ) { e.setStatusOf( getResponse() ); } } DTO also correctly handles array values. For example, specifying: public String[] field; allows "field" to be specified more than once: http://server/foo?field=val1&field=val2&;... There are also @Permitted and @Forbidden annotations. For example: @Permitted( onlyIf={"y"} ) public Integer x; @Permitted( onlyIf={"x"} ) public Integer y; This will cause DTO to throw an exception if either "x" or "y" is given without the other. (@Forbidden works similarly, but in reverse.) If there's interest, I'd be willing to donate this code to Restlet. - Paul
