Move getTimeZone() to ToChar and change return values to suitable for this class

h2/src/main/org/h2/util/ToChar.java

@@ -476,6 +476,44 @@ public class ToChar {
         return result[names];
     }
 
+    /**
+     * Returns time zone display name or ID for the specified date-time value.
+     *
+     * @param value
+     *            value
+     * @param tzd
+     *            if {@code true} return TZD (time zone region with Daylight Saving
+     *            Time information included), if {@code false} return TZR (time zone
+     *            region)
+     * @return time zone display name or ID
+     */
+    private static String getTimeZone(Value value, boolean tzd) {
+        if (!(value instanceof ValueTimestampTimeZone)) {
+            TimeZone tz = TimeZone.getDefault();
+            if (tzd) {
+                boolean daylight = tz.inDaylightTime(new java.util.Date());
+                return tz.getDisplayName(daylight, TimeZone.SHORT);
+            }
+            return tz.getID();
+        }
+        int offset = ((ValueTimestampTimeZone) value).getTimeZoneOffsetMins();
+        if (offset == 0) {
+            return "UTC";
+        }
+        StringBuilder b = new StringBuilder(9);
+        b.append("GMT");
+        if (offset < 0) {
+            b.append('-');
+            offset = - offset;
+        } else {
+            b.append('+');
+        }
+        StringUtils.appendZeroPadded(b, 2, offset / 60);
+        b.append(':');
+        StringUtils.appendZeroPadded(b, 2, offset % 60);
+        return b.toString();
+    }
+
     /**
      * Emulates Oracle's TO_CHAR(datetime) function.
      *
@@ -755,15 +793,10 @@ public class ToChar {
                 // Time zone
 
             } else if (containsAt(format, i, "TZR") != null) {
-                TimeZone tz = value instanceof ValueTimestampTimeZone ?
-                        ((ValueTimestampTimeZone) value).getTimeZone() : TimeZone.getDefault();
-                output.append(tz.getID());
+                output.append(getTimeZone(value, false));
                 i += 3;
             } else if (containsAt(format, i, "TZD") != null) {
-                TimeZone tz = value instanceof ValueTimestampTimeZone ?
-                        ((ValueTimestampTimeZone) value).getTimeZone() : TimeZone.getDefault();
-                boolean daylight = tz.inDaylightTime(new java.util.Date());
-                output.append(tz.getDisplayName(daylight, TimeZone.SHORT));
+                output.append(getTimeZone(value, true));
                 i += 3;
 
                 // Week

h2/src/main/org/h2/value/ValueTimestampTimeZone.java

@@ -9,13 +9,10 @@ import java.math.BigDecimal;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.sql.Timestamp;
-import java.util.SimpleTimeZone;
-import java.util.TimeZone;
 import org.h2.api.ErrorCode;
 import org.h2.api.TimestampWithTimeZone;
 import org.h2.message.DbException;
 import org.h2.util.DateTimeUtils;
-import org.h2.util.StringUtils;
 
 /**
  * Implementation of the TIMESTAMP WITH TIME ZONE data type.
@@ -149,30 +146,6 @@ public class ValueTimestampTimeZone extends Value {
         return timeZoneOffsetMins;
     }
 
-    /**
-     * Returns compatible offset-based time zone with no DST schedule.
-     *
-     * @return compatible offset-based time zone
-     */
-    public TimeZone getTimeZone() {
-        int offset = timeZoneOffsetMins;
-        if (offset == 0) {
-            return DateTimeUtils.UTC;
-        }
-        StringBuilder b = new StringBuilder(9);
-        b.append("GMT");
-        if (offset < 0) {
-            b.append('-');
-            offset = - offset;
-        } else {
-            b.append('+');
-        }
-        StringUtils.appendZeroPadded(b, 2, offset / 60);
-        b.append(':');
-        StringUtils.appendZeroPadded(b, 2, offset % 60);
-        return new SimpleTimeZone(offset * 60000, b.toString());
-    }
-
     @Override
     public Timestamp getTimestamp() {
         throw new UnsupportedOperationException("unimplemented");