8318569: Add getter methods for Locale and Patterns in ListFormat

Reviewed-by: joehw, rriggs, iris, mli

src/java.base/share/classes/java/text/ListFormat.java

@@ -322,6 +322,26 @@ public final class ListFormat extends Format {
         return new ListFormat(Locale.ROOT, Arrays.copyOf(patterns, PATTERN_ARRAY_LENGTH));
     }
 
+    /**
+     * {@return the {@code Locale} of this ListFormat}
+     *
+     * The {@code locale} is defined by {@link #getInstance(Locale, Type, Style)} or
+     * {@link #getInstance(String[])}.
+     */
+    public Locale getLocale() {
+        return locale;
+    }
+
+    /**
+     * {@return the patterns used in this ListFormat}
+     *
+     * The {@code patterns} are defined by {@link #getInstance(Locale, Type, Style)} or
+     * {@link #getInstance(String[])}.
+     */
+    public String[] getPatterns() {
+        return Arrays.copyOf(patterns, patterns.length);
+    }
+
     /**
      * {@return the string that consists of the input strings, concatenated with the
      * patterns of this {@code ListFormat}}