fix : JSONSchema array item reference defs

core/src/main/java/com/alibaba/fastjson2/schema/ArraySchema.java

@@ -83,7 +83,7 @@ public ArraySchema(JSONObject input, JSONSchema root) {
             additionalItemsSupport = true;
         } else {
             additionalItemsSupport = true;
-            this.itemSchema = JSONSchema.of((JSONObject) items, root);
+            this.itemSchema = JSONSchema.of((JSONObject) items, root != null ? root : this);
         }
 
         if (additionalItems instanceof JSONObject) {

core/src/test/java/com/alibaba/fastjson2/schema/JSONSchemaTest1.java

@@ -0,0 +1,30 @@
+package com.alibaba.fastjson2.schema;
+
+import com.alibaba.fastjson2.JSON;
+import com.alibaba.fastjson2.JSONArray;
+import com.alibaba.fastjson2.JSONObject;
+import org.junit.jupiter.api.Test;
+
+import java.net.URL;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class JSONSchemaTest1 {
+    @Test
+    public void test0() {
+        URL url = JSONSchemaTest.class.getClassLoader().getResource("schema/schema_02.json");
+        JSONObject object = JSON.parseObject(url, JSONObject.class);
+        ArraySchema schema = (ArraySchema) JSONSchema.of(object);
+        assertFalse(schema.isValid("aa"));
+        assertFalse(schema.isValid(-1));
+        assertFalse(schema.isValid(-1L));
+
+        assertTrue(schema.isValid(JSONArray.of()));
+        assertTrue(schema.isValid(JSONArray.of(1)));
+
+        assertFalse(schema.isValid(JSONArray.of("a")));
+        assertFalse(schema.isValid(JSONArray.of(-1)));
+        assertFalse(schema.isValid(JSONArray.of(-1L)));
+    }
+}

core/src/test/resources/schema/schema_02.json

@@ -0,0 +1,10 @@
+{
+    "type": "array",
+    "items": { "$ref": "#/$defs/positiveInteger" },
+    "$defs": {
+        "positiveInteger": {
+            "type": "integer",
+            "exclusiveMinimum": 0
+        }
+    }
+}