Spring Boot error handling mechanism

When the request method is not present

The browser appears with a white label error page

Other clients appear in response to a JSON-formatted text that contains information such as an error code

The browser sends the requested header:

Client Request Header

So that we can distinguish from which.

Principle: Errormvcautoconfiguration automatic configuration for handling errors

The following components are added inside

Defaulterrorattributes

help us share information on the page;    @Override  Public Map<string, object> geterrorattributes (Requestattributes requestattributes,            Boolean Includestacktrace) {        Mapnew linkedhashmap<string, object>();        Errorattributes.put ("timestamp"new  Date ());        Addstatus (Errorattributes, requestattributes);        Adderrordetails (Errorattributes, Requestattributes, includestacktrace);        Addpath (Errorattributes, requestattributes);         return errorattributes;    }

Basicerrorcontroller Processing/error Requests

@Controller @requestmapping ("${server.error.path:${error.path:/error}}") Public classBasicerrorcontroller extends Abstracterrorcontroller {@RequestMapping (produces="text/html")//Generate HTML-type data; The browser sends a request to this method to process     PublicModelandview errorHtml (httpservletrequest request, httpservletresponse response) {Httpstatus Statu S=GetStatus (Request); Map<string, object> model =Collections.unmodifiablemap (geterrorattributes (Request, Isincludestacktrace (request, Mediatype.text_h        (TML)));                Response.setstatus (Status.value ()); //which page to go to as error page, including page address and page contentModelandview Modelandview =Resolveerrorview (Request, response, status, model); return(Modelandview = =NULL?NewModelandview ("Error", model): Modelandview); }

@RequestMapping @ResponseBody//generate JSON data, other clients come to this method to handle;     PublicResponseentity<map<string, object>>error (HttpServletRequest request) {Map<string, object> BODY =geterrorattributes (Request, Isincludestacktrace (request, Mediatype.all)); Httpstatus Status=GetStatus (Request); return NewResponseentity<map<string, object>>(body, status); }

Errorpagecustomizer (Error 4xx,5xx such as system error) came to/error request

@Value ("${error.path:/error}")    private"/error ";  After the system error occurs, the error request is processed; (Web. XML registered page rules for errors)

Defaulterrorviewresolver

@Override PublicModelandview Resolveerrorview (httpservletrequest request, httpstatus status, Map<string, object>model) {Modelandview Modelandview=Resolve (string.valueof (status), model); if(Modelandview = =NULL&&Series_views.containskey (Status.series ())) {Modelandview= Resolve (series_views.Get(Status.series ()), model); }        returnModelandview; }    PrivateModelandview Resolve (String viewName, map<string, object>model) {        //default Springboot can go to find a page? error/404String Errorviewname ="error/"+ViewName; //the template engine resolves this page address by using the template engine to parseTemplateavailabilityprovider Provider = This. Templateavailabilityproviders. Getprovider (Errorviewname, This. ApplicationContext); if(Provider! =NULL) {            //returns the specified view address to Errorviewname when the template engine is available            return NewModelandview (errorviewname, model); }        //The template engine is not available, just find the Errorviewname page under the static Resources folder error/404.html        returnResolveResource (errorviewname, model); }

Steps:

? Once the system appears 4xx or 5xx error, Errorpagecustomizer will take effect (custom error response rule); will come to/error request; it will be basicerrorcontroller . ;

? 1) The response page, which page is to be parsed by defaulterrorviewresolver ;

protectedModelandview Resolveerrorview (httpservletrequest request, httpservletresponse response, httpstatus status, Map< /c13><string, object>model) {    //all the errorviewresolver get Modelandview    for(Errorviewresolver resolver: This. Errorviewresolvers) {Modelandview Modelandview=Resolver.resolveerrorview (Request, status, model); if(Modelandview! =NULL) {         returnModelandview; }   }   return NULL;}

Spring Boot error handling mechanism