ICU-20078 Add JP_ERA_2019 constants, export enableTentativeEra(), add intervalFmt tests with eras

icu4c/source/i18n/japancal.cpp

@@ -61,8 +61,9 @@ UOBJECT_DEFINE_RTTI_IMPLEMENTATION(JapaneseCalendar)
 static const int32_t kGregorianEpoch = 1970;    // used as the default value of EXTENDED_YEAR
 static const char* TENTATIVE_ERA_VAR_NAME = "ICU_ENABLE_TENTATIVE_ERA";
 
-// Initialize global Japanese era data
-static void U_CALLCONV initializeEras(UErrorCode &status) {
+
+// Export the following for use by test code.
+UBool JapaneseCalendar::enableTentativeEra() {
     // Although start date of next Japanese era is planned ahead, a name of
     // new era might not be available. This implementation allows tester to
     // check a new era without era names by settings below (in priority order).
@@ -87,7 +88,13 @@ static void U_CALLCONV initializeEras(UErrorCode &status) {
         includeTentativeEra = TRUE;
     }
 #endif
-    gJapaneseEraRules = EraRules::createInstance("japanese", includeTentativeEra, status);
+    return includeTentativeEra;
+}
+
+
+// Initialize global Japanese era data
+static void U_CALLCONV initializeEras(UErrorCode &status) {
+    gJapaneseEraRules = EraRules::createInstance("japanese", JapaneseCalendar::enableTentativeEra(), status);
     if (U_FAILURE(status)) {
         return;
     }

icu4c/source/i18n/japancal.h

@@ -67,7 +67,14 @@ class JapaneseCalendar : public GregorianCalendar {
 public:
 
     /**
-     * Useful constants for JapaneseCalendar.  
+     * Check environment variable. 
+     * @internal
+     */
+    U_I18N_API static UBool U_EXPORT2 enableTentativeEra(void);
+
+    /**
+     * Useful constants for JapaneseCalendar.
+     * Exported for use by test code.
      * @internal
      */
     U_I18N_API static uint32_t U_EXPORT2 getCurrentEra(void); // the current era

icu4c/source/i18n/unicode/udat.h

@@ -482,6 +482,27 @@ typedef enum UDateFormatStyle {
 #define UDAT_HOUR_TZ                    "jz"
 #endif  /* U_HIDE_DEPRECATED_API */
 
+#ifndef U_HIDE_INTERNAL_API
+/**
+ * Constant for Unicode string name of new (in 2019) Japanese calendar era,
+ * root/English abbreviated version (ASCII-range characters).
+ * @internal
+ */
+#define JP_ERA_2019_ROOT                "Qqqq"
+/**
+ * Constant for Unicode string name of new (in 2019) Japanese calendar era,
+ * Japanese abbreviated version (Han, or fullwidth Latin for testing).
+ * @internal
+ */
+#define JP_ERA_2019_JA                  "\\uFF31\\uFF31"
+/**
+ * Constant for Unicode string name of new (in 2019) Japanese calendar era,
+ * root and Japanese narrow version (ASCII-range characters).
+ * @internal
+ */
+#define JP_ERA_2019_NARROW              "Q"
+#endif  // U_HIDE_INTERNAL_API
+
 /**
  * FieldPosition and UFieldPosition selectors for format fields
  * defined by DateFormat and UDateFormat.

icu4j/main/classes/core/src/com/ibm/icu/text/DateFormat.java

@@ -1311,6 +1311,32 @@ public abstract class DateFormat extends UFormat {
     @Deprecated
     public static final String HOUR_TZ = "jz";
 
+    /**
+     * Constant for Unicode string name of new (in 2019) Japanese calendar era,
+     * root/English abbreviated version (ASCII-range characters).
+     * @internal
+     * @deprecated This API is ICU internal only.
+     */
+    @Deprecated
+    public static final String JP_ERA_2019_ROOT = "Qqqq";
+
+    /**
+     * Constant for Unicode string name of new (in 2019) Japanese calendar era,
+     * Japanese abbreviated version (Han, or fullwidth Latin for testing).
+     * @internal
+     * @deprecated This API is ICU internal only.
+     */
+    @Deprecated
+    public static final String JP_ERA_2019_JA = "\uFF31\uFF31";
+
+    /**
+     * Constant for Unicode string name of new (in 2019) Japanese calendar era,
+     * root and Japanese narrow version (ASCII-range characters).
+     * @internal
+     * @deprecated This API is ICU internal only.
+     */
+    @Deprecated
+    public static final String JP_ERA_2019_NARROW = "Q";
 
     /**
      * Gets the time formatter with the default formatting style

icu4j/main/classes/core/src/com/ibm/icu/util/JapaneseCalendar.java

@@ -231,6 +231,16 @@ public class JapaneseCalendar extends GregorianCalendar {
     private static final EraRules ERA_RULES;
 
     static {
+        ERA_RULES = EraRules.getInstance(CalType.JAPANESE, enableTentativeEra());
+    }
+
+    /**
+     * Check environment variable that enables use of future eras.
+     * @internal
+     * @deprecated This API is ICU internal only.
+     */
+    @Deprecated
+    public static boolean enableTentativeEra() {
         // Although start date of next Japanese era is planned ahead, a name of
         // new era might not be available. This implementation allows tester to
         // check a new era without era names by settings below (in priority order).
@@ -258,8 +268,7 @@ public class JapaneseCalendar extends GregorianCalendar {
             String jdkEraConf = System.getProperty("jdk.calendar.japanese.supplemental.era");
             includeTentativeEra = jdkEraConf != null;
         }
-
-        ERA_RULES = EraRules.getInstance(CalType.JAPANESE, includeTentativeEra);
+        return includeTentativeEra;
     }
 
     /**