SPARQL request parsing

The SPARQLParser class allows to parse SPARQL requests expressed as a String, and generate a SPARQLRequest.

To create a SPARQLRequest from a String:

• First create a SPARQLParser
• Then parse the request by SPARQLParser.parseQuery(String request)
• Or use SPARQLParser.parseQuery(URL) or SPARQLParser.parseQuery(URL, String) to parse the SPARQL request which is defined in an URL^[1]
  The SPARQLParser.parseQuery(URL, String) method allows to specify the charset to use when parsing the URL, the SPARQLParser.parseQuery(URL) method assume an UTF-8 encoded content

Parser creation options

There are several options to create the parser:

• The SPARQLParser(String prefix) creates a parser with a default prefix. By default the PREFIX declarations at the beginning of the request will not be parsed
• The SPARQLParser(String prefix, boolean parsePrefix) creates a parser with a default prefix. The parsePrefix argument specifies if the PREFIX declarations at the beginning of the request will be parsed
• The SPARQLParser(String prefix, SparqlPrefixDeclarations decl) creates a parser with a default prefix. The decl argument specifies how and if the PREFIX declarations at the beginning of the request will be parsed

Parsing comments

By default comments in the SPARQL content are not parsed. The SPARQLParser.setParseComments(boolean parseComments) method allow to keep comments during parsing. Alternatively the SPARQLParser(String prefix, boolean parsePrefix, boolean parseComments) allow to manage the prefix and comments parsing.

Example

Suppose the following SPARQL request as a String:

   SELECT ?zone
   WHERE {
     ?zone rdf:type sitac:TaskZone .
     ?zone sitac:isTasked "true" .
   }

To parse this request, we can do:

   SPARQLParser parser = new SPARQLParser("sitac");
   SparqlRequest request = parser.parseQuery(<the request String>);

Unsupported constructs

For the moment, some constructs are yet not supported in SPARQL requests parsing. It does not mean that the parsing will fail, but the result will be incorrect in these cases.

Malformed requests

The SparqlHelperConfig.setErrorsHandlingType(char errorsHandlingType) specifies how the SPARQLParser should behave for malformed requests.