Mark stable and document java.text.DateFormat

Bug: 154796679
Test: m update-api
Change-Id: I268152a73a98fc59ea392430c341f789db9702ef

3 files changed, 20 insertions, 4 deletions

diff --git a/mmodules/core_platform_api/api/stable_platform/current.txt b/mmodules/core_platform_api/api/stable_platform/current.txt
index 07164af03c9..1b4960fe18c 100644
--- a/mmodules/core_platform_api/api/stable_platform/current.txt
+++ b/mmodules/core_platform_api/api/stable_platform/current.txt
@@ -410,6 +410,14 @@ package java.security {
 
 }
 
+package java.text {
+
+  public abstract class DateFormat extends java.text.Format {
+    method public static final void set24HourTimePref(Boolean);
+  }
+
+}
+
 package java.util.concurrent {
 
   public class CompletableFuture<T> implements java.util.concurrent.CompletionStage<T> java.util.concurrent.Future<T> {
diff --git a/ojluni/annotations/mmodule/java/text/DateFormat.annotated.java b/ojluni/annotations/mmodule/java/text/DateFormat.annotated.java
index 5a28d02c787..6456c83fd9d 100644
--- a/ojluni/annotations/mmodule/java/text/DateFormat.annotated.java
+++ b/ojluni/annotations/mmodule/java/text/DateFormat.annotated.java
@@ -83,7 +83,7 @@ public static final java.text.DateFormat getDateTimeInstance(int dateStyle, int
 
 public static final java.text.DateFormat getInstance() { throw new RuntimeException("Stub!"); }
 
-@libcore.api.CorePlatformApi
+@libcore.api.CorePlatformApi(status = libcore.api.CorePlatformApi.Status.STABLE)
 public static final void set24HourTimePref(java.lang.Boolean is24Hour) { throw new RuntimeException("Stub!"); }
 
 public static java.util.Locale[] getAvailableLocales() { throw new RuntimeException("Stub!"); }
diff --git a/ojluni/src/main/java/java/text/DateFormat.java b/ojluni/src/main/java/java/text/DateFormat.java
index d7d5081b541..8622c2f9522 100644
--- a/ojluni/src/main/java/java/text/DateFormat.java
+++ b/ojluni/src/main/java/java/text/DateFormat.java
@@ -600,13 +600,21 @@ public abstract class DateFormat extends Format {
      */
     public static Boolean is24Hour;
 
+    // BEGIN Android-changed: Improve javadoc for stable SystemApi.
     /**
-     * Override the time formatting behavior for SHORT and MEDIUM time formats.
-     * {@code null}: use Locale default. {@code true}: force 24-hour format.
-     * {@code false} force 12-hour format.
+     * Override the time formatting behavior for {@link #SHORT} and {@link #MEDIUM} time formats.
+     * Accepts one of the following:
+     * <ul>
+     *   <li>{@code null}: use Locale default/li>
+     *   <li>{@code true}: force 24-hour format</li>
+     *   <li>{@code false} force 12-hour format</li>
+     * </ul>
+     *
+     * @param is24Hour whether to use 24-hour format or not. {@code null} uses locale default.
      *
      * @hide for internal use only.
      */
+    // END Android-changed: Improve javadoc for stable SystemApi.
     public static final void set24HourTimePref(Boolean is24Hour) {
         DateFormat.is24Hour = is24Hour;
     }