limit supported sparql output types to application/json, application/ld+json

Author: dennisvang

src/main/java/nl/dtls/fairdatapoint/api/controller/search/SearchSparqlController.java

@@ -36,7 +36,6 @@
 
 package nl.dtls.fairdatapoint.api.controller.search;
 
-import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.servlet.http.HttpServletResponse;
 import org.eclipse.rdf4j.http.server.readonly.sparql.EvaluateResult;
@@ -57,6 +56,8 @@ public class SearchSparqlController {
 
     private static final String[] ALL_GRAPHS = {};
 
+    private static final String JSON_MEDIA_TYPES = "application/json, application/ld+json";
+
     private final Repository rdf4jRepository;
 
     private final SparqlQueryEvaluator sparqlQueryEvaluator;
@@ -72,19 +73,23 @@ public SearchSparqlController(Repository rdf4jRepository, SparqlQueryEvaluator s
     /**
      * Allows authenticated users to POST a full SPARQL query.
      * Method body copied from org.eclipse.rdf4j.http.server.readonly.QueryResponder.
-     * The "Accept" header is required, and allowable values depend on the type of query,
+     * The "Accept" header is required, and allowable media types depend on the type of query,
      * as defined in <code>org.eclipse.rdf4j.http.server.readonly.sparql.QueryTypes.formats</code>.
+     * However, to simplify things, we restrict the allowable media types to JSON and/or JSON-LD.
      */
     @PreAuthorize("isAuthenticated()")
-    @PostMapping(path = "/search/sparql", consumes = MediaType.APPLICATION_JSON_VALUE)
+    @PostMapping(
+            path = "/search/sparql",
+            consumes = MediaType.APPLICATION_JSON_VALUE,
+            produces = { MediaType.APPLICATION_JSON_VALUE, "application/ld+json" }
+    )
     public void sparqlPost(
-        @Schema(example = MediaType.APPLICATION_JSON_VALUE)
-            @RequestHeader(value = HttpHeaders.ACCEPT) String acceptHeader,
+        @RequestHeader(value = HttpHeaders.ACCEPT, defaultValue = JSON_MEDIA_TYPES) String acceptHeader,
         @RequestBody SparqlQuery sparqlQuery,
         HttpServletResponse response
     ) throws IOException {
         // enforce default accept header for wildcard
-        final String accept = ("*/*".equals(acceptHeader)) ? MediaType.APPLICATION_JSON_VALUE : acceptHeader;
+        final String accept = ("*/*".equals(acceptHeader)) ? JSON_MEDIA_TYPES : acceptHeader;
         try {
             final EvaluateResultHttpResponse result = new EvaluateResultHttpResponse(response);
             sparqlQueryEvaluator.evaluate(

src/test/java/nl/dtls/fairdatapoint/acceptance/search/sparql/TestSearchSparqlController.java

@@ -72,15 +72,16 @@ public void postSparqlUnauthenticated() throws JsonProcessingException {
         assertTrue(responseBodyMap.containsKey("error"));
     }
 
-    @Test
-    public void postSparqlSelectAll() throws JsonProcessingException {
+    @ParameterizedTest
+    @ValueSource(strings = { MediaType.APPLICATION_JSON_VALUE, "*/*" })
+    public void postSparqlSelectAll(String acceptHeader) throws JsonProcessingException {
         // prepare request
         SearchSparqlController.SparqlQuery sparqlQuery = new SearchSparqlController.SparqlQuery(
                 querySelectAll, null, null);
         RequestEntity<SearchSparqlController.SparqlQuery> request = RequestEntity
                 .post(url)
                 .header(HttpHeaders.AUTHORIZATION, ALBERT_TOKEN)
-                .accept(MediaType.APPLICATION_JSON)
+                .accept(MediaType.valueOf(acceptHeader))
                 .contentType(MediaType.APPLICATION_JSON)
                 .body(sparqlQuery);
 
@@ -127,8 +128,8 @@ public void postSparqlAskAny() throws JsonProcessingException {
 
     @ParameterizedTest
     @ValueSource(strings = {
-            "CONSTRUCT WHERE { ?s a <https://w3id.org/fdp/fdp-o#MetadataService> } ",
-            "DESCRIBE ?s WHERE { ?s a <https://w3id.org/fdp/fdp-o#MetadataService> } "
+            "CONSTRUCT WHERE { ?s a <https://w3id.org/fdp/fdp-o#MetadataService> }",
+            "DESCRIBE ?s WHERE { ?s a <https://w3id.org/fdp/fdp-o#MetadataService> }"
     })
     public void postSparqlConstructOrDescribe(String query) throws JsonProcessingException {
         // prepare request