server: Fix handling of null parameters

Handle null parameters as empty parameters map and let the endpoints
handle execute handling of the empty parameters.

Fixes #235

Signed-off-by: Bernd Hufmann <[email protected]>

Author: bhufmann

trace-server/org.eclipse.tracecompass.incubator.trace.server.jersey.rest.core.tests/src/org/eclipse/tracecompass/incubator/trace/server/jersey/rest/core/tests/utils/RestServerTest.java

@@ -118,11 +118,21 @@ public abstract class RestServerTest {
      */
     protected static final Comparator<DataProvider> DP_COMPARATOR = (p1, p2) -> p1.getName().compareTo(p2.getName());
 
+    /**
+     * the Query parameters key for "parameters"
+     */
+    protected static final String PARAMETER_KEY = "parameters";
+
     /**
      * No parameter string
      */
     protected static final String NO_PARAMETERS = "no-parameters";
 
+    /**
+     * Parameters with null parameter value
+     */
+    protected static final Map<String, Object> NULL_PARAMETERS = Collections.singletonMap(PARAMETER_KEY, null);
+
     /**
      * Invalid experiment UUID
      */
@@ -1131,12 +1141,26 @@ protected static void executePostErrorTests (UUID expUuid, IEndpointResolver res
         }
 
         if (hasParameters) {
+            // Missing parameters
+            endpoint = resolver.getEndpoint(expUuid.toString(), dpId);
+            try (Response response = endpoint.request().post(Entity.json(NULL_PARAMETERS))) {
+                assertNotNull(response);
+                assertEquals(Status.BAD_REQUEST.getStatusCode(), response.getStatus());
+            }
+
             // Missing parameters
             endpoint = resolver.getEndpoint(expUuid.toString(), dpId);
             try (Response response = endpoint.request().post(Entity.json(new QueryParameters(parameters, Collections.emptyList())))) {
                 assertNotNull(response);
                 assertEquals(Status.BAD_REQUEST.getStatusCode(), response.getStatus());
             }
+        } else {
+            // Test null parameters. Since endpoint doesn't require parameters, this should not cause an error reply
+            endpoint = resolver.getEndpoint(expUuid.toString(), dpId);
+            try (Response response = endpoint.request().post(Entity.json(NULL_PARAMETERS))) {
+                assertNotNull(response);
+                assertEquals(Status.OK.getStatusCode(), response.getStatus());
+            }
         }
 
         // Unknown data provider

trace-server/org.eclipse.tracecompass.incubator.trace.server.jersey.rest.core/src/org/eclipse/tracecompass/incubator/internal/trace/server/jersey/rest/core/model/views/QueryParameters.java

@@ -26,7 +26,7 @@
  * @author Simon Delisle
  */
 public class QueryParameters {
-    private @NonNull Map<String, Object> parameters;
+    private @Nullable Map<String, Object> parameters;
     private List<Filter> filters;
 
     /**
@@ -55,7 +55,13 @@ public QueryParameters(Map<String, Object> parameters, List<Filter> filters) {
      */
     @Hidden
     public @NonNull Map<String, Object> getParameters() {
-        return parameters;
+        // Treat null parameters sent by the client as empty parameters map
+        Map<String, Object> params = parameters;
+        if (params == null) {
+            params = new HashMap<>();
+            parameters = params;
+        }
+        return params ;
     }
 
     /**