review comments, and unit tests

Author: sureshanaparti

core/src/main/java/com/cloud/serializer/GsonHelper.java

@@ -22,6 +22,7 @@
 import java.util.List;
 
 import com.cloud.hypervisor.Hypervisor;
+import com.cloud.utils.DateUtil;
 import org.apache.cloudstack.transport.HypervisorTypeAdaptor;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.LogManager;
@@ -50,8 +51,6 @@ public class GsonHelper {
     protected static final Gson s_gson;
     protected static final Gson s_gogger;
 
-    public static final String DATE_FORMAT = "yyyy-MM-dd'T'HH:mm:ssZ";
-
     static {
         GsonBuilder gsonBuilder = new GsonBuilder();
         s_gson = setDefaultGsonConfig(gsonBuilder);
@@ -80,7 +79,7 @@ static Gson setDefaultGsonConfig(GsonBuilder builder) {
         }.getType(), new NwGroupsCommandTypeAdaptor());
         builder.registerTypeAdapter(Storage.StoragePoolType.class, new StoragePoolTypeAdaptor());
         builder.registerTypeAdapter(Hypervisor.HypervisorType.class, new HypervisorTypeAdaptor());
-        builder.setDateFormat(DATE_FORMAT);
+        builder.setDateFormat(DateUtil.ZONED_DATETIME_FORMAT);
         Gson gson = builder.create();
         dsAdaptor.initGson(gson);
         dtAdaptor.initGson(gson);

core/src/test/java/com/cloud/serializer/GsonHelperTest.java

@@ -19,10 +19,14 @@
 
 import com.cloud.agent.api.to.NfsTO;
 import com.cloud.storage.DataStoreRole;
+import com.cloud.utils.DateUtil;
 import com.google.gson.Gson;
 import org.junit.Before;
 import org.junit.Test;
 
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
@@ -78,4 +82,51 @@ public void testGsonLoggerDeserialization() {
         assertEquals("http://example.com", deserializedNfsTO.getUrl());
         assertEquals(DataStoreRole.Primary, deserializedNfsTO.getRole());
     }
+
+    @Test
+    public void testGsonDateFormatSerialization() {
+        Date now = new Date();
+        TestClass testObj = new TestClass("TestString", 999, now);
+        String json = gson.toJson(testObj);
+
+        assertTrue(json.contains("TestString"));
+        assertTrue(json.contains("999"));
+        String expectedDate = new SimpleDateFormat(DateUtil.ZONED_DATETIME_FORMAT).format(now);
+        assertTrue(json.contains(expectedDate));
+    }
+
+    @Test
+    public void testGsonDateFormatDeserialization() throws Exception {
+        String json = "{\"str\":\"TestString\",\"num\":999,\"date\":\"2025-08-22T15:39:43+0000\"}";
+        TestClass testObj = gson.fromJson(json, TestClass.class);
+
+        assertEquals("TestString", testObj.getStr());
+        assertEquals(999, testObj.getNum());
+        Date expectedDate = new SimpleDateFormat(DateUtil.ZONED_DATETIME_FORMAT).parse("2025-08-22T15:39:43+0000");
+        assertEquals(expectedDate, testObj.getDate());
+    }
+
+    private static class TestClass {
+        private String str;
+        private int num;
+        private Date date;
+
+        public TestClass(String str, int num, Date date) {
+            this.str = str;
+            this.num = num;
+            this.date = date;
+        }
+
+        public String getStr() {
+            return str;
+        }
+
+        public int getNum() {
+            return num;
+        }
+
+        public Date getDate() {
+            return date;
+        }
+    }
 }

server/src/main/java/com/cloud/server/StatsCollector.java

@@ -46,6 +46,7 @@
 
 import javax.inject.Inject;
 
+import com.cloud.utils.DateUtil;
 import org.apache.cloudstack.engine.subsystem.api.storage.DataStore;
 import org.apache.cloudstack.engine.subsystem.api.storage.DataStoreManager;
 import org.apache.cloudstack.engine.subsystem.api.storage.DataStoreProvider;
@@ -294,7 +295,7 @@ public String toString() {
     private static StatsCollector s_instance = null;
 
     private static Gson gson = new GsonBuilder()
-            .setDateFormat(GsonHelper.DATE_FORMAT)
+            .setDateFormat(DateUtil.ZONED_DATETIME_FORMAT)
             .create();
 
     private ScheduledExecutorService _executor = null;

utils/src/main/java/com/cloud/utils/DateUtil.java

@@ -48,7 +48,7 @@ public class DateUtil {
 
     public static final TimeZone GMT_TIMEZONE = TimeZone.getTimeZone("GMT");
     public static final String YYYYMMDD_FORMAT = "yyyyMMddHHmmss";
-    private static final String ZONED_DATETIME_FORMAT = "yyyy-MM-dd'T'HH:mm:ssZ";
+    public static final String ZONED_DATETIME_FORMAT = "yyyy-MM-dd'T'HH:mm:ssZ";
     private static final DateFormat ZONED_DATETIME_SIMPLE_FORMATTER = new SimpleDateFormat(ZONED_DATETIME_FORMAT);
 
     private static final DateTimeFormatter[] parseFormats = new DateTimeFormatter[]{