Fix #2643: add colon in timezone offset for better ISO-8601 compliance

release-notes/VERSION-2.x

@@ -42,8 +42,14 @@ Project: jackson-databind
  (reported by Bartosz B)
 #2592: `ObjectMapper.setSerializationInclusion()` is ignored for `JsonAnyGetter`
  (reported by Oleksii K)
+#2643: Change default textual serialization of `java.util.Date`/`Calendar`
+  to include colon in timezone offset
 - Add `SerializerProvider.findContentValueSerializer()` methods
 
+2.10.4 (not yet released)
+
+-
+
 2.10.3 (03-Mar-2020)
 
 #2482: `JSONMappingException` `Location` column number is one line Behind the actual

src/main/java/com/fasterxml/jackson/databind/util/StdDateFormat.java

@@ -17,12 +17,14 @@
  * an ISO-8601 compliant format (format String "yyyy-MM-dd'T'HH:mm:ss.SSSZ")
  * and for deserialization, both ISO-8601 and RFC-1123.
  *<br>
- * Note that `Z` in format String refers to RFC-822 timezone notation which produces
- * values like "-0800" -- that is, full minute/hour combo without colon, and not using `Z`
- * as alias for "+0000".
- *<p>
- * Note also that to enable use of colon in timezone is possible by using method
- * {@link #withColonInTimeZone} for creating new differently configured format instance.
+ * Note that `Z` in format String refers to ISO-8601 time offset notation which produces
+ * values like "-08:00" -- that is, full minute/hour combo without colon, and not using `Z`
+ * as alias for "+00:00".
+ * Inclusion of colon as separator, as default setting, started in Jackson 2.11:
+ * prior versions omitted it.
+ * Note that it is possible to enable/disable use of colon in time offset by using method
+ * {@link #withColonInTimeZone} for creating new differently configured format instance,
+ * and configuring {@code ObjectMapper} with it.
  */
 @SuppressWarnings("serial")
 public class StdDateFormat
@@ -153,11 +155,12 @@ public class StdDateFormat
     /** 
      * Whether the TZ offset must be formatted with a colon between hours and minutes ({@code HH:mm} format)
      *<p>
-     * Defaults to {@code false} for backwards compatibility reasons
+     * Defaults to {@code true} since 2.11: earlier versions defaulted to {@code false}
+     * for backwards compatibility reasons
      *
      * @since 2.9.1
      */
-    private boolean _tzSerializedWithColon = false;
+    private boolean _tzSerializedWithColon = true;
 
     /*
     /**********************************************************

src/test/java/com/fasterxml/jackson/databind/ser/jdk/DateSerializationTest.java

@@ -176,21 +176,22 @@ public void testDateISO8601_customTZ() throws IOException
     /**
      * Configure the StdDateFormat to serialize TZ offset with a colon between hours and minutes
      *
-     * See [databind#1744]
+     * See [databind#1744], [databind#2643]
      */
     public void testDateISO8601_colonInTZ() throws IOException
     {
+        // with [databind#2643], default now is to include
         StdDateFormat dateFormat = new StdDateFormat();
-        assertFalse(dateFormat.isColonIncludedInTimeZone());
-        dateFormat = dateFormat.withColonInTimeZone(true);
         assertTrue(dateFormat.isColonIncludedInTimeZone());
+        // but we can disable it
+        dateFormat = dateFormat.withColonInTimeZone(false);
 
         ObjectMapper mapper = new ObjectMapper();
         mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
         mapper.setDateFormat(dateFormat);
 
-        serialize( mapper, judate(1970, 1, 1,  02, 00, 00, 0, "GMT+2"), "1970-01-01T00:00:00.000+00:00");
-        serialize( mapper, judate(1970, 1, 1,  00, 00, 00, 0, "UTC"),   "1970-01-01T00:00:00.000+00:00");
+        serialize(mapper, judate(1970, 1, 1,  02, 00, 00, 0, "GMT+2"), "1970-01-01T00:00:00.000+0000");
+        serialize(mapper, judate(1970, 1, 1,  00, 00, 00, 0, "UTC"),   "1970-01-01T00:00:00.000+0000");
     }
 
     public void testDateOther() throws IOException
@@ -384,7 +385,7 @@ private void serialize(ObjectWriter w, Object date, String expected) throws IOEx
 
     private String zoneOffset(String raw) {
         // Add colon or not -- difference between 2.10 and earlier, 2.11 and later
-//        return raw.substring(0, 2) + ":" + raw.substring(2); // 2.11 and later
-        return raw; // 2.10 and earlier
+        return raw.substring(0, 2) + ":" + raw.substring(2); // 2.11 and later
+//        return raw; // 2.10 and earlier
     }
 }