Get Multiple Files From One (1) APEX HTTPRequest

Question

I have working code below that initiates 1 HTTPRequest and returns 1 File then emails that one file to multiple users. However, I am now looking to (if possible) initiate 1 HTTPRequest and return multiple files.

I could loop over the HTTPRequest changing the file location however that does not get me to 1 HTTPRequest to multiple files.

I have provided the email portion of my code for completion.

My SFDC version is Enterprise.

Any help would be greatly appreciated.

String location = 'Reports/'.$fileName.'.xls'
// Instantiate a new http object
        Http h = new Http();
        String url = 'http://www.mysite.com/'+location;   
    // Instantiate a new HTTP request, specify the method (GET) as well as the endpoint
        HttpRequest req = new HttpRequest();
        HttpResponse res = new HttpResponse();
        req.setEndpoint(url);
        req.setMethod('GET');

    // Send the request, and return a response
        Boolean error = false;
        String errorMessage = '';
        Blob theData = Blob.valueof(errorMessage);
        try{
            res = h.send(req);
        }catch(system.CalloutException e){
                system.debug('Callout Error: '+e);
                system.debug(res.toString());
                error = true;
                errorMessage = res.toString();
        }

        if(error != true){
            theData = res.getBodyAsBlob(); 

            for(Contact theUser : emailRecipients){
                Messaging.SingleEmailMessage m = new Messaging.SingleEmailMessage();
                m.setTargetObjectId(theUser.id);
                Messaging.EmailFileAttachment a = new Messaging.EmailFileAttachment();
                a.setBody(theData);
                a.setFileName(fileName);
                a.setInline(false);
                m.setFileAttachments(new Messaging.EmailFileAttachment[] { a } );

                m.setSubject('Updated List - '+fileName);
                m.setHtmlBody(emailBodyPrePend+staticEmailBody);
                m.setPlainTextBody(emailBodyPrePend+staticEmailBody);

                m.setSaveAsActivity(false);
                Messaging.sendEmail(new Messaging.SingleEmailMessage[] { m } );
            }

            //send to  useres
            for(User theInternalUser : emailUserRecipients){
                Messaging.SingleEmailMessage m = new Messaging.SingleEmailMessage();
                m.setTargetObjectId(theInternalUser.id);
                Messaging.EmailFileAttachment a = new Messaging.EmailFileAttachment();
                a.setBody(theData);
                a.setFileName(fileName);
                a.setInline(false);
                m.setFileAttachments(new Messaging.EmailFileAttachment[] { a } );

                m.setSubject('Updated List - '+fileName);
                m.setHtmlBody(emailBodyPrePend+staticEmailBody);
                m.setPlainTextBody(emailBodyPrePend+staticEmailBody);

                m.setSaveAsActivity(false);
                Messaging.sendEmail(new Messaging.SingleEmailMessage[] { m } );
            }

        }
        else{
                Messaging.SingleEmailMessage m = new Messaging.SingleEmailMessage();
                m.setTargetObjectId(errorUser.id);
                Messaging.EmailFileAttachment a = new Messaging.EmailFileAttachment();
                a.setBody(theData);
                a.setFileName(fileName);
                a.setInline(false);
                m.setFileAttachments(new Messaging.EmailFileAttachment[] { a } );
                m.setSubject('ERROR OCCURED WHEN SENDING NOTICES: '+fileName);
                m.setPlainTextBody('ERROR MESSAGE: '+errorMessage);

                m.setSaveAsActivity(false);
                Messaging.sendEmail(new Messaging.SingleEmailMessage[] { m } );
        }

Answer 1

The "REST" interface in Apex Code doesn't support pipelining, SPDY, or asynchronous callbacks, so there's no way to retrieve more than one file per request natively. If you were feeling bold, you could probably develop a custom service (externally) that you could call out to as a proxy that could retrieve multiple resources, string them together in a single response, and feed that back into salesforce.com. Short of doing this, there's no other way you're going to get more than one file per HttpRequest/HttpResponse pair. You can have up to 10 callouts per transaction, so you can retrieve up to ten files natively (with a total collective size of 3MB). Performing a loop would be the correct approach to this.