Add note to Java SDK

source/includes/note-java-maintenance-mode.rst

@@ -0,0 +1,8 @@
+.. note:: Java SDK in Maintenance Mode
+
+   The Java SDK is in best-effort maintenance mode and no longer receives 
+   new development or non-critical bug fixes. To develop your app with new 
+   features, use the :ref:`Kotlin SDK <kotlin-intro>`. You can use the Java SDK 
+   with the Kotlin SDK in the same project. 
+
+   Learn more about how to :ref:`<kotlin-migrate-from-java-sdk-to-kotlin-sdk>`. 

source/sdk/java.txt

@@ -38,6 +38,8 @@ Realm Java SDK
    :depth: 2
    :class: singlecol
 
+.. include:: /includes/note-java-maintenance-mode.rst
+
 Use the Realm Java SDK to develop Android apps in Java or Kotlin. To develop
 multiplatform apps using Kotlin Multiplatform (KMP), refer to the
 :ref:`Realm Kotlin SDK <kotlin-intro>`.

source/sdk/java/install.txt

@@ -10,12 +10,20 @@ Install Realm - Java SDK
    :depth: 2
    :class: singlecol
 
+.. include:: /includes/note-java-maintenance-mode.rst 
+
 Overview
 --------
 
-This page details how to install Realm in your project
+This page details how to install Realm using the Java SDK in your project
 and get started.
 
+You can use multiple SDKs in your project. Because the Java SDK is no longer
+receiving new development, this is useful if you want to 
+use new features in your app. For example, you can add Atlas 
+Device Sync's :ref:`Data Ingest <optimize-data-ingest>` feature to your 
+app using the Kotlin SDK while continuing to use Java for everything else.  
+
 Prerequisites
 -------------