Merge pull request #3812 from senivam/3804

issue 3804 fix (SelectableEntityFiltering when the fields specified is . character)

examples/entity-filtering-selectable/src/test/java/org/glassfish/jersey/examples/entityfiltering/selectable/PersonResourceTest.java

@@ -136,6 +136,28 @@ public void testFilters() throws Exception {
         assertThat(entity.getRegion(), nullValue());
     }
 
+    /**
+     * Test empty (but valid) filters.
+     * Valid empty filters are:
+     *  . ,. , .. .,
+     *
+     *
+     * result is empty object (nothing is returned) but Jersey will not throw any exception
+     */
+    @Test
+    public void testEmptyFilters() throws Exception {
+        final Person entity = target("people").path("1234")
+                .queryParam("select", ".").request()
+                .get(Person.class);
+
+        // Null values (all elements).
+        assertThat(entity.getFamilyName(), nullValue());
+        assertThat(entity.getGivenName(), nullValue());
+        assertThat(entity.getAddresses(), nullValue());
+        assertThat(entity.getPhoneNumbers(), nullValue());
+        assertThat(entity.getRegion(), nullValue());
+    }
+
     /**
      * Test 2nd and 3rd level filters.
      */

ext/entity-filtering/src/main/java/org/glassfish/jersey/message/filtering/SelectableScopeResolver.java

@@ -83,6 +83,9 @@ private Set<String> getScopesForField(final String fieldName) {
         final String[] fields = Tokenizer.tokenize(fieldName, ",");
         for (final String field : fields) {
             final String[] subfields = Tokenizer.tokenize(field, ".");
+            if (subfields.length == 0) {
+                continue;
+            }
             // in case of nested path, add first level as stand-alone to ensure subgraph is added
             scopes.add(SelectableScopeResolver.PREFIX + subfields[0]);
             if (subfields.length > 1) {