[LMS-328]

add: - time zone to registration date.

SVN: 5519

common/source/java/ch/systemsx/cisd/common/utilities/DateTimeUtils.java

+/*
+ * Copyright 2008 ETH Zuerich, CISD
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.systemsx.cisd.common.utilities;
+
+import java.util.Calendar;
+import java.util.Date;
+
+import org.apache.commons.lang.time.DateUtils;
+
+/**
+ * A suite of utilities surrounding the use of the {@link java.util.Calendar} and
+ * {@link java.util.Date} object.
+ * 
+ * @author Christian Ribeaud
+ */
+public final class DateTimeUtils
+{
+    /**
+     * Returns the time zone in the following form: <code>GMT+01:00</code> (could not be easily
+     * performed with <i>Java</i>).
+     */
+    public final static String getTimeZone(final Date date)
+    {
+        assert date != null : "Unspecified date.";
+        final Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+        final StringBuffer zoneString = new StringBuffer();
+        int value = calendar.get(Calendar.ZONE_OFFSET) + calendar.get(Calendar.DST_OFFSET);
+        if (value < 0)
+        {
+            zoneString.append('-');
+            // Suppress the '-' sign for text display.
+            value = -value;
+        } else
+        {
+            zoneString.append('+');
+        }
+        int num = value / (int) DateUtils.MILLIS_PER_HOUR;
+        zoneString.append(prependZeroIfNeeded(num));
+        zoneString.append(":");
+        num = (value % (int) DateUtils.MILLIS_PER_HOUR) / (int) DateUtils.MILLIS_PER_MINUTE;
+        zoneString.append(prependZeroIfNeeded(num));
+        return "GMT" + zoneString.toString();
+    }
+
+    private final static String prependZeroIfNeeded(final int num)
+    {
+        return num < 10 ? "0" + num : "" + num;
+    }
+
+}