ArrayEvalFilter: add support for ! (logical negation) operator

json-path/src/main/java/com/jayway/jsonpath/internal/filter/ArrayEvalFilter.java

@@ -96,6 +96,10 @@ public class ArrayEvalFilter extends PathTokenFilter {
     }
 
     static Expression createExpression(String condition) {
+        condition = condition.trim();
+        if (condition.startsWith("!")) {
+            return new NegationExpression(createExpression(condition.substring(1)));
+        }
         Matcher conditionMatcher = CONDITION_PATTERN.matcher(condition);
         if (conditionMatcher.matches()) {
             String property = conditionMatcher.group(1).trim();
@@ -270,4 +274,17 @@ public class ArrayEvalFilter extends PathTokenFilter {
         }
 
     }
+
+    static class NegationExpression extends Expression {
+        private Expression expression;
+
+        public NegationExpression(Expression expression) {
+            this.expression = expression;
+        }
+
+        @Override
+        public boolean evaluate(Object check, Configuration configuration) {
+            return !expression.evaluate(check, configuration);
+        }
+    }
 }

json-path/src/test/java/com/jayway/jsonpath/ComplianceTest.java

@@ -116,10 +116,9 @@ public class ComplianceTest {
                 "             }";
 
         assertThat(JsonPath.<List<String>>read(json, "$.menu.items[?(@ && @.id == 'ViewSVG')].id"), hasItems("ViewSVG"));
-
-        //assertThat(JsonPath.<List<String>>read(json, "$.menu.items[?(@ && @.id && !@.label)].id"), hasItems("?")); //low
-        assertThat(JsonPath.<List<String>>read(json, "$.menu.items[?(@ && @.label && /SVG/.test(@.label))].id"), hasItems("CopySVG", "ViewSVG")); //low
-        //assertThat(JsonPath.<List<String>>read(json, "$.menu.items[?(!@)]"), hasItems("?")); //low
+        assertThat(JsonPath.<List<String>>read(json, "$.menu.items[?(@ && @.id && !@.label)].id"), hasItems("Open", "Quality", "Pause", "Mute", "Copy", "Help"));
+        assertThat(JsonPath.<List<String>>read(json, "$.menu.items[?(@ && @.label && /SVG/.test(@.label))].id"), hasItems("CopySVG", "ViewSVG"));
+        assertThat(JsonPath.<List<String>>read(json, "$.menu.items[?(!@)]"), hasItems((String)null, (String)null, (String)null, (String)null));
         //assertThat(JsonPath.<List<String>>read(json, "$..[0]"), hasItems("?")); //low
 
     }