Match more time-zone IDs (#733)

* Match some more IDs from java.time.* * Fixes #717
JodaOrg · Aug 28, 2023 · 0e251d2 · 0e251d2
1 parent 806da07
commit 0e251d2
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Showing 2 changed files with 44 additions and 11 deletions.
diff --git a/src/main/java/org/joda/time/DateTimeZone.java b/src/main/java/org/joda/time/DateTimeZone.java
@@ -215,11 +215,13 @@ public static void setDefault(DateTimeZone zone) throws SecurityException {
      * <p>
      * The time zone id may be one of those returned by getAvailableIDs.
      * Short ids, as accepted by {@link java.util.TimeZone}, are not accepted.
-     * All IDs must be specified in the long format.
-     * The exception is UTC, which is an acceptable id.
+     * All IDs must be specified in the long format unless detailed below.
      * <p>
-     * Alternatively a locale independent, fixed offset, datetime zone can
-     * be specified. The form <code>[+-]hh:mm</code> can be used.
+     * A locale independent, fixed offset, datetime zone can be specified
+     * using the form <code>[+-]hh:mm</code>.
+     * The offset may be prefixed by 'UTC', 'GMT' or 'UT'.
+     * In addition, the IDs 'Z', 'UTC', 'GMT' and 'UT' will return a UTC
+     * equivalent time-zone.
      * 
      * @param id  the ID of the datetime zone, null means default
      * @return the DateTimeZone object for the ID
@@ -237,13 +239,25 @@ public static DateTimeZone forID(String id) {
         if (zone != null) {
             return zone;
         }
-        if (id.startsWith("+") || id.startsWith("-")) {
-            int offset = parseOffset(id);
+        // compatibility with more ZoneId values
+        // note that GMT normally matches to Etc/GMT in the block above, but if the
+        // time-zone provider has been replaced and does not match GMT then this line will
+        if (id.equals("UT") || id.equals("GMT") || id.equals("Z")) {
+            return DateTimeZone.UTC;
+        }
+        String idToParse = id;
+        if (id.startsWith("UTC+") || id.startsWith("UTC-") || id.startsWith("GMT+") || id.startsWith("GMT-")) {
+            idToParse = id.substring(3);
+        } else if (id.startsWith("UT+") || id.startsWith("UT-")) {
+            idToParse = id.substring(2);
+        }
+        if (idToParse.startsWith("+") || idToParse.startsWith("-")) {
+            int offset = parseOffset(idToParse);
             if (offset == 0L) {
                 return DateTimeZone.UTC;
             } else {
-                id = printOffset(offset);
-                return fixedOffsetZone(id, offset);
+                idToParse = printOffset(offset);
+                return fixedOffsetZone(idToParse, offset);
             }
         }
         throw new IllegalArgumentException("The datetime zone id '" + id + "' is not recognised");

diff --git a/src/test/java/org/joda/time/TestDateTimeZone.java b/src/test/java/org/joda/time/TestDateTimeZone.java
@@ -205,17 +205,36 @@ public void testForID_String() {
         zone = DateTimeZone.forID("UTC");
         assertSame(DateTimeZone.UTC, zone);
 
+        zone = DateTimeZone.forID("UT");
+        assertSame(DateTimeZone.UTC, zone);
+
+        zone = DateTimeZone.forID("Z");
+        assertSame(DateTimeZone.UTC, zone);
+
+        zone = DateTimeZone.forID("GMT");
+        // depends if the default time-zone provider has been changed or not
+        assertTrue(zone == DateTimeZone.forID("Etc/GMT") || zone == DateTimeZone.UTC);
+
         zone = DateTimeZone.forID("+00:00");
         assertSame(DateTimeZone.UTC, zone);
 
         zone = DateTimeZone.forID("+00");
         assertSame(DateTimeZone.UTC, zone);
 
+        long expected = DateTimeConstants.MILLIS_PER_HOUR + (23L * DateTimeConstants.MILLIS_PER_MINUTE);
         zone = DateTimeZone.forID("+01:23");
         assertEquals("+01:23", zone.getID());
-        assertEquals(DateTimeConstants.MILLIS_PER_HOUR + (23L * DateTimeConstants.MILLIS_PER_MINUTE),
-                zone.getOffset(TEST_TIME_SUMMER));
-
+        assertEquals(expected, zone.getOffset(TEST_TIME_SUMMER));
+        zone = DateTimeZone.forID("GMT+01:23");
+        assertEquals("+01:23", zone.getID());
+        assertEquals(expected, zone.getOffset(TEST_TIME_SUMMER));
+        zone = DateTimeZone.forID("UTC+01:23");
+        assertEquals("+01:23", zone.getID());
+        assertEquals(expected, zone.getOffset(TEST_TIME_SUMMER));
+        zone = DateTimeZone.forID("UT+01:23");
+        assertEquals("+01:23", zone.getID());
+        assertEquals(expected, zone.getOffset(TEST_TIME_SUMMER));
+
         zone = DateTimeZone.forID("-02:00");
         assertEquals("-02:00", zone.getID());
         assertEquals((-2L * DateTimeConstants.MILLIS_PER_HOUR),