EHN: add timezone info to Info Resource

src/main/java/caosdb/datetime/UTCTimeZoneShift.java

@@ -111,4 +111,17 @@ public class UTCTimeZoneShift extends TimeZone {
   public String getID() {
     return str;
   }
+
+  /**
+   * Generate an ISO 8601 time zone offset string (e.g. +0200) from the given raw offset in
+   * milliseconds.
+   *
+   * @param rawOffset - offset in ms.
+   * @return ISO 8601 time zone offset.
+   */
+  public static String getISO8601Offset(int rawOffset) {
+    int h = Integer.divideUnsigned(rawOffset, 1000 * 60 * 60);
+    int m = Integer.remainderUnsigned(rawOffset, 1000 * 60 * 60);
+    return generateString(Integer.signum(h), h, m);
+  }
 }

src/main/java/caosdb/server/resource/InfoResource.java

@@ -22,10 +22,12 @@
  */
 package caosdb.server.resource;
 
+import caosdb.datetime.UTCTimeZoneShift;
 import caosdb.server.database.backend.implementation.MySQL.ConnectionException;
 import caosdb.server.database.misc.TransactionBenchmark;
 import caosdb.server.utils.FlagInfo;
 import caosdb.server.utils.Info;
+import java.util.TimeZone;
 import org.jdom2.Document;
 import org.jdom2.Element;
 import org.jdom2.JDOMException;
@@ -43,6 +45,7 @@ public class InfoResource extends AbstractCaosDBServerResource {
   protected Representation httpGetInChildClass() throws Exception {
     final Document doc = new Document();
     final Element root = generateRootElement();
+    root.addContent(getTimeZone());
     root.addContent(Info.toElement());
     root.addContent(FlagInfo.toElement());
     root.addContent(TransactionBenchmark.getRootInstance().toElememt());
@@ -50,6 +53,14 @@ public class InfoResource extends AbstractCaosDBServerResource {
     return ok(doc);
   }
 
+  public Element getTimeZone() {
+    TimeZone d = TimeZone.getDefault();
+    return new Element("TimeZone")
+        .setAttribute("offset", UTCTimeZoneShift.getISO8601Offset(d.getRawOffset()))
+        .setAttribute("id", d.getID())
+        .addContent(d.getDisplayName());
+  }
+
   /** There is no POST request specified for the /Info resource. */
   @Override
   protected Representation httpPostInChildClass(final Representation entity)