java - How to output an error message in my JSF page, related to my httpresponse error -

i have logic code (putting error response):

    public modelandview resolveexception(httpservletrequest request, httpservletresponse response, object handler,         exception ex) {     boolean maxsizeex = true;     if (ex instanceof maxuploadsizeexceededexception) {         logger.debug("tried upload file exceeded capacity", ex);     } else {         logger.warn("caught unexpected exception", ex);         maxsizeex = false;     }      final boolean fmaxsizeex = maxsizeex;     view view = new view() {         public void render(map model, httpservletrequest request, httpservletresponse response) throws exception {             map<string, string> data = new hashmap<string, string>();             if (fmaxsizeex) {                 data.put("error", "limit size exceeded");             } else {                 data.put("error", "internal error");             }             jsonapicontroller.maptojsonandoutput(response.getoutputstream(), data);         }          public string getcontenttype() {             return "application/json";         }     };     return new modelandview(view); } 

and want after that, output error message in view (my jsf page).

how can in jsf page ?

here code of maptojsonandoutput method :

protected static void maptojsonandoutput(outputstream out, map<string, string> data) throws ioexception {     if (data == null || data.isempty()) {         logger.warn("you should not call maptojsonandoutput if there no data");         return;     }     jsonfactory f = new jsonfactory();     jsongenerator g = f.createjsongenerator(out, jsonencoding.utf8);     g.writestartobject();     (entry<string, string> e : data.entryset()) {         g.writestringfield(e.getkey(), e.getvalue());     }     g.writeendobject();     g.flush();     devispdfresourcecontroller.close(out); } 

thanks help.

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edit :

if (fmaxsizeex) {             data.put("error", "limit size exceeded");         } else {             data.put("error", "internal error");         }         jsonapicontroller.maptojsonandoutput(response.getoutputstream(), data) 

the code data.put("error", "limit size exceeded") seems not working, want add error message response.

any suggestions ?

i don't know if simplest method in case, there's jsf tag called <h:messages> can display facescontext message 4 levels of severity.

see documentation : http://www.jsftoolbox.com/documentation/help/12-tagreference/html/h_messages.html

here's how works in simple case :

view (.jsf) :

 <h:messages /> 

controller (.java) :

 facesmessage message = new facesmessage(facesmessage.your_severity, "your description", "your message");  facescontext.getcurrentinstance().addmessage(null, message);