Fix FasterXML#915

Author: cowtowncoder

release-notes/VERSION

@@ -14,6 +14,8 @@ Project: jackson-databind
  (reported by Miles K)
 #497: Add new JsonInclude.Include feature to exclude maps after exclusion removes all elements
 #819: Add support for setting `FormatFeature` via `ObjectReader`, `ObjectWriter`
+#915: ObjectMapper default timezone is GMT, should be UTC
+ (suggested by Infrag@github)
 #918: Add `MapperFeature.ALLOW_EXPLICIT_PROPERTY_RENAMING`
  (contributed by David H)
 #924: `SequenceWriter.writeAll()` could accept `Iterable`

src/main/java/com/fasterxml/jackson/databind/SequenceWriter.java

@@ -196,9 +196,9 @@ public SequenceWriter writeAll(Object[] value) throws IOException
         return this;
     }
 
-    @Deprecated
-    public <C extends Collection<?>> SequenceWriter writeAll(C container) throws IOException
-    {
+    // NOTE: redundant wrt variant that takes Iterable, but can not remove or even
+    // deprecate due to backwards-compatibility needs
+    public <C extends Collection<?>> SequenceWriter writeAll(C container) throws IOException {
         for (Object value : container) {
             write(value);
         }

src/main/java/com/fasterxml/jackson/databind/cfg/BaseSettings.java

@@ -31,10 +31,10 @@ public final class BaseSettings
      */
     private static final TimeZone DEFAULT_TIMEZONE = 
             //  TimeZone.getDefault()
-            /* [databind#915] 26-Sep-2015, tatu: Should be UTC, plan to change
-             * it so for 2.7
+            /* [databind#915] 05-Nov-2015, tatu: Changed to UTC, from earlier
+             * baseline of GMT (up to 2.6)
              */
-            TimeZone.getTimeZone("GMT");
+            TimeZone.getTimeZone("UTC");
 
     /*
     /**********************************************************

src/main/java/com/fasterxml/jackson/databind/util/ISO8601Utils.java

@@ -14,32 +14,36 @@
  */
 public class ISO8601Utils
 {
-    /**
-     * ID to represent the 'GMT' string
-     */
+    @Deprecated // since 2.7
     private static final String GMT_ID = "GMT";
 
     /**
-     * @since 2.6
+     * ID to represent the 'UTC' string, default timezone since Jackson 2.7
+     * 
+     * @since 2.7
      */
-//    private static final String UTC_ID = "UTC";
+    private static final String UTC_ID = "UTC";
 
     /**
      * The GMT timezone, prefetched to avoid more lookups.
+     * 
+     * @deprecated Since 2.7 use {@link #TIMEZONE_UTC} instead
      */
+    @Deprecated
     private static final TimeZone TIMEZONE_GMT = TimeZone.getTimeZone(GMT_ID);
 
     /**
      * The UTC timezone, prefetched to avoid more lookups.
      * 
-     * @since 2.6
+     * @since 2.7
      */
-//    private static final TimeZone TIMEZONE_UTC = TimeZone.getTimeZone(UTC_ID);
+    private static final TimeZone TIMEZONE_UTC = TimeZone.getTimeZone(UTC_ID);
 
     /**
-     * Timezone we use for 'Z' in ISO-8601 date/time values.
+     * Timezone we use for 'Z' in ISO-8601 date/time values: since 2.7
+     * {@link #TIMEZONE_UTC}; with earlier versions up to 2.7 was {@link #TIMEZONE_GMT}.
      */
-    private static final TimeZone TIMEZONE_Z = TIMEZONE_GMT;
+    private static final TimeZone TIMEZONE_Z = TIMEZONE_UTC;
 
     /*
     /**********************************************************
@@ -64,13 +68,13 @@ public static TimeZone timeZoneGMT() {
      */
 
     /**
-     * Format a date into 'yyyy-MM-ddThh:mm:ssZ' (GMT timezone, no milliseconds precision)
+     * Format a date into 'yyyy-MM-ddThh:mm:ssZ' (default timezone, no milliseconds precision)
      * 
      * @param date the date to format
      * @return the date formatted as 'yyyy-MM-ddThh:mm:ssZ'
      */
     public static String format(Date date) {
-        return format(date, false, TIMEZONE_GMT);
+        return format(date, false, TIMEZONE_UTC);
     }
 
     /**
@@ -81,15 +85,15 @@ public static String format(Date date) {
      * @return the date formatted as 'yyyy-MM-ddThh:mm:ss[.sss]Z'
      */
     public static String format(Date date, boolean millis) {
-        return format(date, millis, TIMEZONE_GMT);
+        return format(date, millis, TIMEZONE_UTC);
     }
 
     /**
      * Format date into yyyy-MM-ddThh:mm:ss[.sss][Z|[+-]hh:mm]
      * 
      * @param date the date to format
      * @param millis true to include millis precision otherwise false
-     * @param tz timezone to use for the formatting (GMT will produce 'Z')
+     * @param tz timezone to use for the formatting (UTC will produce 'Z')
      * @return the date formatted as yyyy-MM-ddThh:mm:ss[.sss][Z|[+-]hh:mm]
      */
     public static String format(Date date, boolean millis, TimeZone tz) {
@@ -243,9 +247,14 @@ public static Date parse(String date, ParsePosition pos) throws ParseException {
                     timezone = TIMEZONE_Z;
                 } else {
                     // 18-Jun-2015, tatu: Looks like offsets only work from GMT, not UTC...
-                    //    not sure why, but it is what it is.
-                    String timezoneId = GMT_ID + timezoneOffset;
+                    //    not sure why, but that's the way it looks. Further, Javadocs for
+                    //    `java.util.TimeZone` specifically instruct use of GMT as base for
+                    //    custom timezones... odd.
+                    String timezoneId = "GMT" + timezoneOffset;
+//                    String timezoneId = "UTC" + timezoneOffset;
+
                     timezone = TimeZone.getTimeZone(timezoneId);
+
                     String act = timezone.getID();
                     if (!act.equals(timezoneId)) {
                         /* 22-Jan-2015, tatu: Looks like canonical version has colons, but we may be given

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

@@ -35,7 +35,7 @@ public class StdDateFormat
 
     /**
      * Same as 'regular' 8601, but handles 'Z' as an alias for "+0000"
-     * (or "GMT")
+     * (or "UTC")
      */
     protected final static String DATE_FORMAT_STR_ISO8601_Z = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'";
 
@@ -61,11 +61,12 @@ public class StdDateFormat
     };
 
     /**
-     * By default we use GMT for everything.
+     * By default we use UTC for everything, with Jackson 2.7 and later
+     * (2.6 and earlier relied on GMT)
      */
     private final static TimeZone DEFAULT_TIMEZONE;
     static {
-        DEFAULT_TIMEZONE = TimeZone.getTimeZone("GMT");
+        DEFAULT_TIMEZONE = TimeZone.getTimeZone("UTC"); // since 2.7
     }
 
     private final static Locale DEFAULT_LOCALE = Locale.US;
@@ -82,7 +83,7 @@ public class StdDateFormat
      * actual instances more cheaply (avoids re-parsing).
      */
     static {
-        /* Another important thing: let's force use of GMT for
+        /* Another important thing: let's force use of default timezone for
          * baseline DataFormat objects
          */
 
@@ -170,18 +171,6 @@ public StdDateFormat clone() {
         return new StdDateFormat(_timezone, _locale);
     }
 
-    /**
-     * Method for getting the globally shared DateFormat instance
-     * that uses GMT timezone and can handle simple ISO-8601
-     * compliant date format.
-     * 
-     * @deprecated Since 2.4 not to be used.
-     */
-    @Deprecated
-    public static DateFormat getBlueprintISO8601Format() {
-        return DATE_FORMAT_ISO8601;
-    }
-
     /**
      * @deprecated Since 2.4; use variant that takes Locale
      */
@@ -200,18 +189,6 @@ public static DateFormat getISO8601Format(TimeZone tz) {
     public static DateFormat getISO8601Format(TimeZone tz, Locale loc) {
         return _cloneFormat(DATE_FORMAT_ISO8601, DATE_FORMAT_STR_ISO8601, tz, loc);
     }
-    
-    /**
-     * Method for getting the globally shared DateFormat instance
-     * that uses GMT timezone and can handle RFC-1123
-     * compliant date format.
-     * 
-     * @deprecated Since 2.4 not to be used.
-     */
-    @Deprecated
-    public static DateFormat getBlueprintRFC1123Format() {
-        return DATE_FORMAT_RFC1123;
-    }
 
     /**
      * Method for getting a non-shared DateFormat instance
@@ -367,9 +344,9 @@ protected Date parseAsISO8601(String dateStr, ParsePosition pos)
          * timezone  modifiers for ISO-8601. So we need to do some scrubbing.
          */
 
-        /* First: do we have "zulu" format ('Z' == "GMT")? If yes, that's
+        /* First: do we have "zulu" format ('Z' == "UTC")? If yes, that's
          * quite simple because we already set date format timezone to be
-         * GMT, and hence can just strip out 'Z' altogether
+         * UTC, and hence can just strip out 'Z' altogether
          */
         int len = dateStr.length();
         char c = dateStr.charAt(len-1);