@Override
protected final void perform(HttpAction action) {
// OPTIONS
if (action.request.getMethod().equals(HttpNames.METHOD_OPTIONS)) {
// Share with update via SPARQL_Protocol.
doOptions(action);
return;
}
// GET
if (action.request.getMethod().equals(HttpNames.METHOD_GET)) {
executeWithParameter(action);
return;
}
ContentType ct = FusekiLib.getContentType(action);
// POST application/x-www-form-url
// POST ?query= and no Content-Type
if (ct == null || isHtmlForm(ct)) {
// validation checked that if no Content-type, then its a POST with ?query=
executeWithParameter(action);
return;
}
// POST application/sparql-query
if (matchContentType(ct, ctSPARQLQuery)) {
executeBody(action);
return;
}
ServletOps.error(HttpSC.UNSUPPORTED_MEDIA_TYPE_415, "Bad content type: " + ct.getContentType());
}
protected void execute(String queryString, HttpAction action) {
String queryStringLog = ServletOps.formatForLog(queryString);
if (action.verbose) action.log.info(format("[%d] Query = \n%s", action.id, queryString));
else action.log.info(format("[%d] Query = %s", action.id, queryStringLog));
Query query = null;
try {
// NB syntax is ARQ (a superset of SPARQL)
query = QueryFactory.create(queryString, QueryParseBase, Syntax.syntaxARQ);
queryStringLog = formatForLog(query);
validateQuery(action, query);
} catch (ActionErrorException ex) {
throw ex;
} catch (QueryParseException ex) {
ServletOps.errorBadRequest(
"Parse error: \n" + queryString + "\n\r" + messageForQueryException(ex));
}
// Should not happen.
catch (QueryException ex) {
ServletOps.errorBadRequest("Error: \n" + queryString + "\n\r" + ex.getMessage());
}
// Assumes finished whole thing by end of sendResult.
try {
action.beginRead();
Dataset dataset = decideDataset(action, query, queryStringLog);
try (QueryExecution qExec = createQueryExecution(query, dataset); ) {
SPARQLResult result = executeQuery(action, qExec, query, queryStringLog);
// Deals with exceptions itself.
sendResults(action, result, query.getPrologue());
}
} catch (QueryParseException ex) {
// Late stage static error (e.g. bad fixed Lucene query string).
ServletOps.errorBadRequest(
"Query parse error: \n" + queryString + "\n\r" + messageForQueryException(ex));
} catch (QueryCancelledException ex) {
// Additional counter information.
incCounter(action.getEndpoint().getCounters(), QueryTimeouts);
throw ex;
} finally {
action.endRead();
}
}
protected void executeBody(HttpAction action) {
String queryString = null;
try {
InputStream input = action.request.getInputStream();
queryString = IO.readWholeFileAsUTF8(input);
} catch (IOException ex) {
ServletOps.errorOccurred(ex);
}
execute(queryString, action);
}
/**
* Ship the results to the remote caller.
*
* @param action
* @param result
* @param qPrologue
*/
protected void sendResults(HttpAction action, SPARQLResult result, Prologue qPrologue) {
if (result.isResultSet())
ResponseResultSet.doResponseResultSet(action, result.getResultSet(), qPrologue);
else if (result.isDataset())
// CONSTRUCT is processed as a extended CONSTRUCT - result is a dataset.
ResponseDataset.doResponseDataset(action, result.getDataset());
else if (result.isModel())
// DESCRIBE results are models
ResponseDataset.doResponseModel(action, result.getModel());
else if (result.isBoolean())
ResponseResultSet.doResponseResultSet(action, result.getBooleanResult());
else ServletOps.errorOccurred("Unknown or invalid result type");
}
/**
* Validate the request, checking HTTP method and HTTP Parameters.
*
* @param action HTTP Action
*/
@Override
protected void validate(HttpAction action) {
String method = action.request.getMethod().toUpperCase(Locale.ROOT);
if (HttpNames.METHOD_OPTIONS.equals(method)) return;
if (!HttpNames.METHOD_POST.equals(method) && !HttpNames.METHOD_GET.equals(method))
ServletOps.errorMethodNotAllowed("Not a GET or POST request");
if (HttpNames.METHOD_GET.equals(method) && action.request.getQueryString() == null) {
ServletOps.warning(
action, "Service Description / SPARQL Query / " + action.request.getRequestURI());
ServletOps.errorNotFound("Service Description: " + action.request.getRequestURI());
}
// Use of the dataset describing parameters is check later.
try {
validateParams(action, allParams);
validateRequest(action);
} catch (ActionErrorException ex) {
throw ex;
}
// Query not yet parsed.
}
/**
* Perform the {@link QueryExecution} once.
*
* @param action
* @param queryExecution
* @param query
* @param queryStringLog Informational string created from the initial query.
* @return
*/
protected SPARQLResult executeQuery(
HttpAction action, QueryExecution queryExecution, Query query, String queryStringLog) {
setAnyTimeouts(queryExecution, action);
if (query.isSelectType()) {
ResultSet rs = queryExecution.execSelect();
// Force some query execution now.
// If the timeout-first-row goes off, the output stream has not
// been started so the HTTP error code is sent.
rs.hasNext();
// If we wanted perfect query time cancellation, we could consume
// the result now to see if the timeout-end-of-query goes off.
// rs = ResultSetFactory.copyResults(rs) ;
// action.log.info(format("[%d] exec/select", action.id)) ;
return new SPARQLResult(rs);
}
if (query.isConstructType()) {
Dataset dataset = queryExecution.execConstructDataset();
// action.log.info(format("[%d] exec/construct", action.id));
return new SPARQLResult(dataset);
}
if (query.isDescribeType()) {
Model model = queryExecution.execDescribe();
// action.log.info(format("[%d] exec/describe", action.id)) ;
return new SPARQLResult(model);
}
if (query.isAskType()) {
boolean b = queryExecution.execAsk();
// action.log.info(format("[%d] exec/ask", action.id)) ;
return new SPARQLResult(b);
}
ServletOps.errorBadRequest("Unknown query type - " + queryStringLog);
return null;
}
/**
* Helper method for validating request.
*
* @param request HTTP request
* @param params parameters in a collection of Strings
*/
protected void validateParams(HttpAction action, Collection<String> params) {
HttpServletRequest request = action.request;
ContentType ct = FusekiLib.getContentType(request);
boolean mustHaveQueryParam = true;
if (ct != null) {
String incoming = ct.getContentType();
if (matchContentType(ctSPARQLQuery, ct)) {
mustHaveQueryParam = false;
// Drop through.
} else if (matchContentType(ctHTMLForm, ct)) {
// Nothing specific to do
} else ServletOps.error(HttpSC.UNSUPPORTED_MEDIA_TYPE_415, "Unsupported: " + incoming);
}
// GET/POST of a form at this point.
if (mustHaveQueryParam) {
int N = countParamOccurences(request, paramQuery);
if (N == 0) ServletOps.errorBadRequest("SPARQL Query: No 'query=' parameter");
if (N > 1) ServletOps.errorBadRequest("SPARQL Query: Multiple 'query=' parameters");
// application/sparql-query does not use a query param.
String queryStr = request.getParameter(HttpNames.paramQuery);
if (queryStr == null)
ServletOps.errorBadRequest("SPARQL Query: No query specified (no 'query=' found)");
if (queryStr.isEmpty()) ServletOps.errorBadRequest("SPARQL Query: Empty query string");
}
if (params != null) {
Enumeration<String> en = request.getParameterNames();
for (; en.hasMoreElements(); ) {
String name = en.nextElement();
if (!params.contains(name))
ServletOps.warning(
action, "SPARQL Query: Unrecognize request parameter (ignored): " + name);
}
}
}
