Fix json pointer with number in fragment (#1077)

Author: justin-tay

src/main/java/com/networknt/schema/utils/JsonNodes.java

@@ -67,7 +67,7 @@ public static <T extends JsonNode> T get(JsonNode node, JsonNodePath path) {
     @SuppressWarnings("unchecked")
     public static <T extends JsonNode> T get(JsonNode node, Object propertyOrIndex) {
         JsonNode value = null;
-        if (propertyOrIndex instanceof Number) {
+        if (propertyOrIndex instanceof Number && node.isArray()) {
             value = node.get(((Number) propertyOrIndex).intValue());
         } else {
             value = node.get(propertyOrIndex.toString());

src/test/java/com/networknt/schema/oas/OpenApi30Test.java

@@ -16,6 +16,7 @@
 package com.networknt.schema.oas;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 import java.util.List;
 import java.util.Set;
@@ -64,4 +65,16 @@ void validateMetaSchema() {
         assertEquals("required", list.get(1).getType());
         assertEquals("bark", list.get(1).getProperty());
     }
+
+    /**
+     * Tests that schema location with number in fragment can resolve.
+     */
+    @Test
+    void jsonPointerWithNumberInFragment() {
+        JsonSchemaFactory factory = JsonSchemaFactory.getInstance(VersionFlag.V7, builder -> builder
+                .metaSchema(OpenApi30.getInstance()).defaultMetaSchemaIri(OpenApi30.getInstance().getIri()));
+        JsonSchema schema = factory.getSchema(SchemaLocation.of(
+                "classpath:schema/oas/3.0/petstore.yaml#/paths/~1pet/post/responses/200/content/application~1json/schema"));
+        assertNotNull(schema);
+    }
 }