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javasparqlrdfrdf4j

How can I find out the type of sparql query using the code?



String qb = "PREFIX dc: <http://purl.org/dc/elements/1.1/>\n" +
                "INSERT DATA\n" +
                "{ \n" +
                "  <http://example/book1> dc:title \"A new book\" ;\n" +
                "                         dc:creator \"A.N.Other\" .\n" +
                "}";

// Here I need to check what type of query I got
String type = ... //some code for checking

if (type == "select") {
   ParsedTupleQuery q = (ParsedTupleQuery)parser.parseQuery(qb, null);
}else if(type == "costruct") {
   ParsedGraphQuery q = (ParsedGraphQuery)parser.parseQuery(qb, null);
}else if(type == "update"){ //here can be insert or delete
   ParsedUpdate q = parser.parseUpdate(qb, null);
}

I can't find a way to find out what type of query it is. Maybe somebody's ever seen it before?


Solution

  • Rdf4j has a QueryParserUtil with a convenience method for this. You can use it as follows:

    ParsedOperation operation = QueryParserUtil.parseOperation(QueryLanguage.SPARQL, qb, null); 
    if (operation instanceof ParsedTupleQuery) {
       ParsedTupleQuery q = (ParsedTupleQuery)operation;
       ...
    } else if (operation instanceof ParsedGraphQuery) {
       ParsedGraphQuery q = (ParsedGraphQuery)operation;
       ...
    } else if (operation instance ParsedUpdate) {
       ParsedUpdate u = (ParsedUpdate)operation;
       ...
    }