Exception in thread "main" HttpException: 404 at
org.apache.jena.sparql.engine.http.HttpQuery.execGet(HttpQuery.java:328
)
404 - HTTP not found - when trying to call Fuseki - i.e. the query
service URL is wrong. A server is running at the address (host:port) but
the path does not name an HTTP resource.
Andy
On 26/12/17 19:00, ajs6f wrote:
I don't understand how that config is getting parsed at all. It's not valid
Turtle.
ja:loadClass "io.bdrc.ldsearch.query.functions.CustomARQFunctions" .
is not a triple at all. It should probably be:
[] ja:loadClass "io.bdrc.ldsearch.query.functions.CustomARQFunctions" .
Riot gives "Expected IRI for predicate: got:
[STRING:io.bdrc.ldsearch.query.functions.CustomARQFunctions]"
It's not clear to me how you could be successfully loading your extension
function with invalid config.
Adam Soroka
On Dec 26, 2017, at 1:42 PM, Marc Agate <agate.m...@gmail.com> wrote:
Well...
Here is the query
PREFIX : <http://purl.bdrc.io/ontology/core/>
PREFIX adm: <http://purl.bdrc.io/ontology/admin/>
PREFIX bdr: <http://purl.bdrc.io/resource/>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX tbr: <http://purl.bdrc.io/ontology/toberemoved/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX f: <java:io.bdrc.ldsearch.query.functions.CustomARQFunctions.>
SELECT DISTINCT ?l
WHERE {
?x skos:prefLabel ?l .
FILTER (f:myFilter(?l) < 100)
}
Note that whene I change FILTER (f:myFilter(?l) < 100) to FILTER
(STRLEN(?l) < 100), I don't get the 404 exception...
Therefore it's not a connection issue. I thing it's more like a
unresolved URI or so.
Now, since you'are asking for it, here is the full fuseki config:
################################################################
# Fuseki configuration for BDRC, configures two endpoints:
# - /bdrc is read-only
# - /bdrcrw is read-write
#
# This was painful to come up with but the web interface basically
allows no option
# and there is no subclass inference by default so such a configuration
file is necessary.
#
# The main doc sources are:
# - https://jena.apache.org/documentation/fuseki2/fuseki-configuration
.html
# - https://jena.apache.org/documentation/assembler/assembler-howto.ht
ml
# - https://jena.apache.org/documentation/assembler/assembler.ttl
#
# See https://jena.apache.org/documentation/fuseki2/fuseki-layout.html
for the destination of this file.
@prefix fuseki: <http://jena.apache.org/fuseki#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix tdb: <http://jena.hpl.hp.com/2008/tdb#> .
# @prefix tdb2: <http://jena.apache.org/2016/tdb#> .
@prefix ja: <http://jena.hpl.hp.com/2005/11/Assembler#> .
@prefix : <http://base/#> .
@prefix text: <http://jena.apache.org/text#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix adm: <http://purl.bdrc.io/ontology/admin/> .
@prefix bdd: <http://purl.bdrc.io/data/> .
@prefix bdo: <http://purl.bdrc.io/ontology/core/> .
@prefix bdr: <http://purl.bdrc.io/resource/> .
@prefix f: <java:io.bdrc.ldsearch.query.functions.CustomARQFunctions.>
.
ja:loadClass "io.bdrc.ldsearch.query.functions.CustomARQFunctions" .
# [] ja:loadClass "org.seaborne.tdb2.TDB2" .
# tdb2:DatasetTDB2 rdfs:subClassOf ja:RDFDataset .
# tdb2:GraphTDB2 rdfs:subClassOf ja:Model .
[] rdf:type fuseki:Server ;
fuseki:services (
:bdrcrw
# :bdrcro
) .
:bdrcrw rdf:type fuseki:Service ;
fuseki:name "bdrcrw" ; # name of the
dataset in the url
fuseki:serviceQuery "query" ; # SPARQL query
service
fuseki:serviceUpdate "update" ; # SPARQL update
service
fuseki:serviceUpload "upload" ; # Non-SPARQL upload
service
fuseki:serviceReadWriteGraphStore "data" ; # SPARQL Graph store
protocol (read and write)
fuseki:dataset :bdrc_text_dataset ;
.
# :bdrcro rdf:type fuseki:Service ;
# fuseki:name "bdrc" ;
# fuseki:serviceQuery "query" ;
# fuseki:serviceReadGraphStore "data" ;
# fuseki:dataset :bdrc_text_dataset ;
# .
# using TDB
:dataset_bdrc rdf:type tdb:DatasetTDB ;
tdb:location "/etc/fuseki/databases/bdrc" ;
tdb:unionDefaultGraph true ;
.
# # try using TDB2
# :dataset_bdrc rdf:type tdb2:DatasetTDB2 ;
# tdb2:location "/etc/fuseki/databases/bdrc" ;
# tdb2:unionDefaultGraph true ;
# .
:bdrc_text_dataset rdf:type text:TextDataset ;
text:dataset :dataset_bdrc ;
text:index :bdrc_lucene_index ;
.
# Text index description
:bdrc_lucene_index a text:TextIndexLucene ;
text:directory <file:/etc/fuseki/lucene-bdrc> ;
text:storeValues true ;
text:multilingualSupport true ;
text:entityMap :bdrc_entmap ;
text:defineAnalyzers (
[ text:addLang "bo" ;
text:analyzer [
a text:GenericAnalyzer ;
text:class "io.bdrc.lucene.bo.TibetanAnalyzer" ;
text:params (
[ text:paramName "segmentInWords" ;
text:paramType text:TypeBoolean ;
text:paramValue false ]
[ text:paramName "lemmatize" ;
text:paramType text:TypeBoolean ;
text:paramValue true ]
[ text:paramName "filterChars" ;
text:paramType text:TypeBoolean ;
text:paramValue false ]
[ text:paramName "fromEwts" ;
text:paramType text:TypeBoolean ;
text:paramValue false ]
)
] ;
]
[ text:addLang "bo-x-ewts" ;
text:analyzer [
a text:GenericAnalyzer ;
text:class "io.bdrc.lucene.bo.TibetanAnalyzer" ;
text:params (
[ text:paramName "segmentInWords" ;
text:paramType text:TypeBoolean ;
text:paramValue false ]
[ text:paramName "lemmatize" ;
text:paramType text:TypeBoolean ;
text:paramValue true ]
[ text:paramName "filterChars" ;
text:paramType text:TypeBoolean ;
text:paramValue false ]
[ text:paramName "fromEwts" ;
text:paramType text:TypeBoolean ;
text:paramValue true ]
)
] ;
]
) ;
.
# Index mappings
:bdrc_entmap a text:EntityMap ;
text:entityField "uri" ;
text:uidField "uid" ;
text:defaultField "label" ;
text:langField "lang" ;
text:graphField "graph" ; ## enable graph-specific indexing
text:map (
[ text:field "label" ;
text:predicate skos:prefLabel ]
[ text:field "altLabel" ;
text:predicate skos:altLabel ; ]
[ text:field "rdfsLabel" ;
text:predicate rdfs:label ; ]
[ text:field "chunkContents" ;
text:predicate bdo:chunkContents ; ]
[ text:field "eTextTitle" ;
text:predicate bdo:eTextTitle ; ]
[ text:field "logMessage" ;
text:predicate adm:logMessage ; ]
[ text:field "noteText" ;
text:predicate bdo:noteText ; ]
[ text:field "workAuthorshipStatement" ;
text:predicate bdo:workAuthorshipStatement ; ]
[ text:field "workColophon" ;
text:predicate bdo:workColophon ; ]
[ text:field "workEditionStatement" ;
text:predicate bdo:workEditionStatement ; ]
[ text:field "workPublisherLocation" ;
text:predicate bdo:workPublisherLocation ; ]
[ text:field "workPublisherName" ;
text:predicate bdo:workPublisherName ; ]
[ text:field "workSeriesName" ;
text:predicate bdo:workSeriesName ; ]
) ;
.
###################################################################
It would be wonderful to have the java:URI scheme thing working (all
custom functions in a single class and method calls done directly in
the sparql query : sounds like a dream !)
Marc
Le mardi 26 décembre 2017 à 13:22 -0500, ajs6f a écrit :
That exception doesn't appear to have anything to do with extension
functions. It indicates a problem between client and server.
Please show at _least_ your actual query execution code, your
complete Fuseki config, and a complete stacktrace.
ajs6f
On Dec 26, 2017, at 1:17 PM, Marc Agate <agate.m...@gmail.com>
wrote:
I forgot to mention that according to
https://jena.apache.org/documentation/query/java-uri.html
I tried for testing purpose to set a PREFIX f:
<java:io.bdrc.ldsearch.query.functions.CustomARQFunctions.>and
added
the following to fuseki config :
ja:loadClass "io.bdrc.ldsearch.query.functions.CustomARQFunctions"
.
where CustomARQFunctions is :
public class CustomARQFunctions { public static
NodeValue myFilter(NodeValue value1){ int i
=
value1.asString().length(); return
NodeValue.makeInteger(i); }
}
since according to
https://jena.apache.org/documentation/query/writing_functions.html
using the java:URI scheme "dynamically loads the code, which must
be on
the Java classpath. With this scheme, the function URI gives the
class
name. There is automatic registration of a wrapper into the
function
registry. This way, no explicit registration step is needed by the
application and queries issues with the command line tools can load
custom functions."
but no luck: I keep getting the following exception:
Exception in thread "main" HttpException: 404 at
org.apache.jena.sparql.engine.http.HttpQuery.execGet(HttpQuery.java
:328
) at
org.apache.jena.sparql.engine.http.HttpQuery.exec(HttpQuery.java:28
8)
at
org.apache.jena.sparql.engine.http.QueryEngineHTTP.execResultSetInn
er(Q
ueryEngineHTTP.java:348) at
org.apache.jena.sparql.engine.http.QueryEngineHTTP.execSelect(Query
Engi
neHTTP.java:340)
I am stuck !
Marc
Le mardi 26 décembre 2017 à 18:56 +0100, Marc Agate a écrit :
Hi,
Adam's gave me the right direction.
I managed to load my function class in fuseki config using
ja:loadClass
but now remains the following issue (the function is not
registered)seefuseki logs :
[2017-12-26 16:10:13] exec WARN URI <http://purl.bdrc.io/f
unct
ions#MyFilterFunction> has no registered function factory
How can I register this function now that I have the code
available
onthe endpoint side ?
Thanks for helping
Marc.
Le mardi 26 décembre 2017 à 17:43 +0000, Andy Seaborne a écrit :
As well s Adam's point (and all the libraries your function
needs, transitively)
What is in the Fuseki log file?How was the data loaded into
Fuseki?
>> I printed out the >> FunctionRegistry
And
On 26/12/17 14:51, ajs6f wrote:
I'm not as familiar with the extension points of ARQ as I
wouldlike to be, but as I understand what you are doing, you
areregistering a new function with your _local_ registry,
then
firinga query at a _remote_ endpoint (which has a completely
independentregistry in a different JVM in a different
process,
potentially ina different _system_).
The query is getting interpreted and executed by that
remoteservice, not locally. So you need to register the
function
_there_.
Take a look at this thread:
https://lists.apache.org/thread.html/1cda23332af4264883e88697
d994
605770edcde2f93ddea51240e4b8@%3Cusers.jena.apache.org%3E
It should get you started as to how to register
extensionfunctionality in Fuseki.
Adam Soroka
On Dec 26, 2017, at 9:34 AM, Marc Agate <agate.marc@gmail.c
om>
wrote:
Hi !
I successfully implemented sparql queries using custom ARQ
functions
using the following (custom function code):
****************
public class LevenshteinFilter extends FunctionBase2 {
public LevenshteinFilter() { super() ; }
public NodeValue exec(NodeValue value1, NodeValue
value2){
LevenshteinDistance LD=new LevenshteinDistance();
int i = LD.apply(value1.asString(),
value2.asString());
return NodeValue.makeInteger(i);
}
}
***************
it works fine when I query against a Model loaded from a
turtle
file,
like this:
***************
InputStream input =
QueryProcessor.class.getClassLoader().getResourceAsStream("
full
.t
tl");
model =
ModelFactory.createMemModelMaker().createModel("default");
model.read(input,null,"TURTLE"); // null base
URI,
since
model URIs are absolute
input.close();
***************
with the query being sent like this :
***************
String functionUri = "http://www.example1.org/LevenshteinFu
ncti
on
";
FunctionRegistry.get().put(functionUri ,
LevenshteinFilter.class);
String s = "whatever you want";
String sparql = prefixes+" SELECT DISTINCT ?l
WHERE {
?x
rdfs:label ?l . " + "FILTER(fct:LevenshteinFunction(?l,
\"" +
s
+ "\")
< 4) }";
Query query = QueryFactory.create(sparql);
QueryExecution qexec =
QueryExecutionFactory.create(query,
model);
ResultSet rs = qexec.execSelect();
***************
However, if i use a working fuseki endpoint for the same
dataset
(full.ttl) like this :
***************
fusekiUrl="http://localhost:3030/ds/query";;
***************
sending the query like this (using
QueryExecutionFactory.sparqlService(fusekiUrl,query)
instead of
QueryExecutionFactory.create(query,model) ):
***************
String functionUri = "http://www.example1.org/LevenshteinFu
ncti
on
";
FunctionRegistry.get().put(functionUri ,
LevenshteinFilter.class);
String s = "whatever you want";
String sparql = prefixes+" SELECT DISTINCT ?l
WHERE {
?x
rdfs:label ?l . " + "FILTER(fct:LevenshteinFunction(?l, \""
+ s
+
"\")
< 4) }";
Query query = QueryFactory.create(sparql);
QueryExecution qexec =
QueryExecutionFactory.sparqlService(fusekiUrl,query);
ResultSet rs = qexec.execSelect();
***************
Then I don't get any results back. In both cases I printed
out
the
FunctionRegistry and they contain exactly the same entries,
especially
:
key=http://www.example1.org/LevenshteinFunction value:
org.apache.jena.sparql.function.FunctionFactoryAuto@5a45133
e
Any clue ?
Thanks
