one seems to be the jetty error + jena error message and the other is the specific jena 'lexical error' message. keep in mind fuseki uses jetty to serve http requests in the standard configuration.
since jena is open source you can inspect the error handle in more detail yourself, show more detailed logging or roll your own. https://github.com/apache/jena/blob/master/jena-arq/src/main/java/org/apache/jena/sparql/lang/arq/TokenMgrError.java On Thu, Nov 29, 2018 at 8:04 AM Vincent Ventresque < [email protected]> wrote: > Thanks a lot for all these elements Andy. > > However, I still don't understand /why the parser works most of the time > and fails sometimes/. Any clue about what's happening? I find it very > strange that re-typing the same query can solve the problem (I don't > change anything but the query string : the endpoint url is the same, > etc). Could it be linked to some http connection problem? > > Another point I'd like to understand : what is exactly the difference > between 'lexical error' and 'parse error' in Fuseki? > > > Le 29/11/2018 à 00:02, Andy Seaborne a écrit : > > The /MyDataset/ is slightly magic. > > > > Fuseki inspects the request and determines if it is a query or an update. > > > > It is a query if: > > 1/ The URL query string of the request URI has ?query= in it. (GET or > > HTML form) > > 2/ The content type is application/sparql-query (POST) > > > > and an update if: > > > > 3/ The URL update string is ?update= (GET or HTML form - GET wil be > > bounced later on). > > 4/ The content type is application/sparql-update (POST) > > > > The code is in ServiceRouter.chooseOperation(HttpAction,DataService) > > > > It returns the determines operation which then is used to direct to > > the request to the right code - query or update. > > > > If sent to /query or /update the Fuseki knows it is a query or update > > directly. There is still checking. > > > > The logs shows the system the system detected the request as a POSTed > > query (from YASQE - Fuseki uses a 3rd part SPARQL javascript editor) > > because it logs "Query =" then parses it as query where DELETE is not > > allowed. > > > > This becomes more important at Fuseki 3.10 because the next version > > supports access control so query vs update matters more. > > > > s-update will send it as an update using POST with the right content > > type. > > > > This is not to do with browsers. > > > > Andy > > > > > > On 28/11/2018 20:13, Vincent Ventresque wrote: > >> Thanks Andy. > >> > >> I don't understand : 'update' queries work in UI most of the time > >> (and when I re-write this 'delete' query, it works... Of course I > >> have to give http://localhost:3030/MyDataset or > >> http://localhost:3030/MyDataset/update as endpoint url (above dialog > >> box), not http://localhost:3030/MyDataset/query). > >> > >> Besides, I'm not sure the problem didn't occur with 'select' or other > >> 'read-only' queries (I'll report the case if it happens). > >> > >> BUT the error message (see here : > >> https://sourceforge.net/projects/ffl-misc/files/fuseki_strange_errors > >> ) says > >> > >> Encountered " "delete" "delete "" at line 19, column 1. > >> Was expecting one of: > >> "base" ... > >> "prefix" ... > >> "select" ... > >> "json" ... > >> "describe" ... > >> "construct" ... > >> "ask" ... > >> (7 ms) > >> > >> and not 'delete', 'insert', so maybe the parser doesn't like updates > >> as you said. > >> > >> -- Another case, maybe irrelevant for this problem, where I get > >> errors : I often try a query in the UI first, and then copy-paste the > >> string in a custom script to reuse it with command-line tools (the > >> script passes the query string to other scripts such as s-query, > >> tdbquery, s-update). I noticed that the 'auto-formatting' > >> (indentation, spaces, code folds, etc) in the UI dialog box inserts > >> 'special characters' and sometimes I have to chop them to get the > >> script working. Maybe there's something wrong with a special > >> character in this 'delete' query too? (N.B. : I don't remember if the > >> error message is 'lexical error' or 'parse error' in this case) > >> > >> -- a final point (don't know if it's relevant either) : I use only > >> Firefox, didn't try with other browsers. Do you think the problem > >> could be linked to javascript or some other piece of the web > >> interface in firefox (maybe a bug in firefox itself) ? > >> > >> > >> Le 28/11/2018 à 14:53, Andy Seaborne a écrit : > >>> Vincent, > >>> > >>> It's a parse because DELETE is SPARQL Update and the query editor is > >>> for query. In SPARQL, they are different languages. > >>> > >>> There is some way (IIRC) to use the UI with update but I can't > >>> remember how - maybe someone else can answer that part. > >>> > >>> Andy > >>> > >>> On 28/11/2018 11:28, Vincent Ventresque wrote: > >>>> Hello, > >>>> > >>>> Sometimes I have a '400 Parse error' when typing a query in Fuseki UI. > >>>> -- Here, the query string 'delete {?s ?p ?o } where {?s ?p ?o }' > >>>> doesn't work at first. N.B.: I hadn't pasted the string from other > >>>> software, everything had been typed in the query dialog box. > >>>> -- If I change the string for a construct query (cut 'delete', type > >>>> 'construct' instead), it's ok. Then I cut 'construct' and type > >>>> 'delete' again, this time it works. > >>>> -- Nothing in log file > >>>> > >>>> > >>>> I get this error with fuseki 3.9.0 and 3.5.0. > >>>> > >>>> I've uploaded a screenshot of the UI + a .txt file where you can > >>>> see the infos (install version, terminal output) : > >>>> https://sourceforge.net/projects/ffl-misc/files/fuseki_strange_errors > >>>> > >>>> Do you have encountered this problem? Do you know where it comes from? > >>>> > >>>> Thanks in advance, > >>>> > >>>> Vincent > >>>> > -- --- Marco Neumann KONA
