backport: reverse conversion of IANA-zones to winzones

see issue #756
MenoData · Mar 17, 2018 · eafd36a · eafd36a
1 parent c151052
commit eafd36a
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Showing 5 changed files with 96 additions and 4 deletions.
diff --git a/core/src/test/java/net/time4j/SystemClockTest.java b/core/src/test/java/net/time4j/SystemClockTest.java
@@ -47,7 +47,7 @@ public void currentTime() {
     public void realTimeInMicros() {
         SystemClock clock = SystemClock.MONOTONIC;
         assertThat(
-            Math.abs(clock.realTimeInMicros() - SystemClock.INSTANCE.realTimeInMicros()) < 1000,
+            Math.abs(clock.realTimeInMicros() - SystemClock.INSTANCE.realTimeInMicros()) < 5000,
             is(true));
         long utc = clock.realTimeInMicros() / 1000000;
         long unix = clock.currentTimeInMicros() / 1000000;

diff --git a/misc/src/main/java/net/time4j/tz/other/WindowsZone.java b/misc/src/main/java/net/time4j/tz/other/WindowsZone.java
@@ -1,6 +1,6 @@
 /*
  * -----------------------------------------------------------------------
- * Copyright © 2013-2015 Meno Hochschild, <http://www.menodata.de/>
+ * Copyright © 2013-2018 Meno Hochschild, <http://www.menodata.de/>
  * -----------------------------------------------------------------------
  * This file (WindowsZone.java) is part of project Time4J.
  *
@@ -21,7 +21,10 @@
 
 package net.time4j.tz.other;
 
+import net.time4j.tz.NameStyle;
 import net.time4j.tz.TZID;
+import net.time4j.tz.Timezone;
+import net.time4j.tz.ZoneNameProvider;
 import net.time4j.tz.spi.WinZoneProviderSPI;
 
 import java.io.IOException;
@@ -45,6 +48,18 @@
  *  // output: WINDOWS~America/New_York
  * </pre>
  *
+ * <p>The <i>reverse</i> way: </p>
+ *
+ * <pre>
+ *  String winzone = WindowsZone.toString(&quot;America/New_York&quot;, Locale.US);
+ *  System.out.println(winzone);
+ *  // output: Eastern Standard Time
+ * </pre>
+ *
+ * <p><strong>Note:</strong> A perfect roundtrip is often not possible because there are many more IANA-zone
+ * identifiers than windows zones. For best results, it is recommended to use the tzdata-module and not the
+ * standard timezone data of the underlying platform. </p>
+ *
  * @author  Meno Hochschild
  * @since   2.2
  */
@@ -61,6 +76,18 @@
  *  // output: WINDOWS~America/New_York
  * </pre>
  *
+ * <p>Der <i>umgekehrte</i> Weg: </p>
+ *
+ * <pre>
+ *  String winzone = WindowsZone.toString(&quot;America/New_York&quot;, Locale.US);
+ *  System.out.println(winzone);
+ *  // output: Eastern Standard Time
+ * </pre>
+ *
+ * <p><strong>Hinweis:</strong> Ein perfekter Kreisweg ist oft nicht m&ouml;glich, weil es viel mehr
+ * IANA-Zeitzonenkennungen als Windows-Zeitzonen gibt. Um beste Ergebnisse zu erzielen, wird empfohlen,
+ * das tzdata-Modul und nicht die Standardzeitzonendaten der jeweiligen Plattform zu nutzen. </p>
+ *
  * @author  Meno Hochschild
  * @since   2.2
  */
@@ -115,6 +142,7 @@ public static Set<String> getAvailableNames() {
      * @throws  IllegalArgumentException if given name is not supported
      * @since   2.2
      * @see     #getAvailableNames()
+     * @see     #toString()
      */
     /*[deutsch]
      * <p>Erzeugt einen Namensbezug zu einer Windows-Zeitzone. </p>
@@ -124,6 +152,7 @@ public static Set<String> getAvailableNames() {
      * @throws  IllegalArgumentException if given name is not supported
      * @since   2.2
      * @see     #getAvailableNames()
+     * @see     #toString()
      */
     public static WindowsZone of(String name) {
 
@@ -170,6 +199,58 @@ public String toString() {
 
     }
 
+    /**
+     * <p>Deduces the windows name of given timezone reference and region. </p>
+     *
+     * @param   tzid    timezone identifier (usually a IANA/Olson-ID like &quot;America/New_York&quot;)
+     * @param   locale  regional setting referring to a country
+     * @return  name of windows zone, maybe empty if resolving fails
+     * @since   3.41/4.36
+     */
+    /*[deutsch]
+     * <p>Leitet den Windows-Namen aus der angegebenen Zeitzonenreferenz in der jeweiligen Region ab. </p>
+     *
+     * @param   tzid    timezone identifier (usually a IANA/Olson-ID like &quot;America/New_York&quot;)
+     * @param   locale  regional setting referring to a country
+     * @return  name of windows zone, maybe empty if resolving fails
+     * @since   3.41/4.36
+     */
+    public static String toString(
+        TZID tzid,
+        Locale locale
+    ) {
+
+        return toString(tzid.canonical(), locale);
+
+    }
+
+    /**
+     * <p>Deduces the windows name of given timezone reference and region. </p>
+     *
+     * @param   tzid    timezone identifier (usually a IANA/Olson-ID like &quot;America/New_York&quot;)
+     * @param   locale  regional setting referring to a country
+     * @return  name of windows zone, maybe empty if resolving fails
+     * @since   3.41/4.36
+     */
+    /*[deutsch]
+     * <p>Leitet den Windows-Namen aus der angegebenen Zeitzonenreferenz in der jeweiligen Region ab. </p>
+     *
+     * @param   tzid    timezone identifier (usually a IANA/Olson-ID like &quot;America/New_York&quot;)
+     * @param   locale  regional setting referring to a country
+     * @return  name of windows zone, maybe empty if resolving fails
+     * @since   3.41/4.36
+     */
+    public static String toString(
+        String tzid,
+        Locale locale
+    ) {
+
+        String zoneID = Timezone.normalize(tzid).canonical();
+        ZoneNameProvider znp = new WinZoneProviderSPI();
+        return znp.getDisplayName(zoneID, NameStyle.LONG_STANDARD_TIME, locale);
+
+    }
+
     /**
      * <p>The natural order is based on the lexicographical order of the
      * underlying names of windows zones. </p>

diff --git a/misc/src/main/java/net/time4j/tz/spi/WinZoneProviderSPI.java b/misc/src/main/java/net/time4j/tz/spi/WinZoneProviderSPI.java
@@ -1,6 +1,6 @@
 /*
  * -----------------------------------------------------------------------
- * Copyright © 2013-2016 Meno Hochschild, <http://www.menodata.de/>
+ * Copyright © 2013-2018 Meno Hochschild, <http://www.menodata.de/>
  * -----------------------------------------------------------------------
  * This file (WinZoneProviderSPI.java) is part of project Time4J.
  *
@@ -153,7 +153,7 @@ public Set<String> getPreferredIDs(
     @Override
     public String getDisplayName(
         String tzid,
-        NameStyle style,
+        NameStyle style, // unused
         Locale locale
     ) {
 

diff --git a/misc/src/main/resources/data/winzone.ser b/misc/src/main/resources/data/winzone.ser
diff --git a/misc/src/test/java/net/time4j/tz/other/WindowsZoneTest.java b/misc/src/test/java/net/time4j/tz/other/WindowsZoneTest.java
@@ -189,6 +189,17 @@ public void normalize() {
             is("America/New_York"));
     }
 
+    @Test
+    public void toStringStatic() {
+        assertThat(
+            WindowsZone.toString(Timezone.of("America/New_York").getID(), Locale.US),
+            is("Eastern Standard Time"));
+        assertThat(
+            WindowsZone.toString("Asia/Kolkata", new Locale("en", "IN")),
+            is("India Standard Time"));
+        // CLDR uses "Asia/Calcutta", but Time4J adjusts it during compiling of winzone-data
+    }
+
     private static Object roundtrip(Object obj)
         throws IOException, ClassNotFoundException {