SDK-5186: Add link and clear Readme

Author: bartek.zylinski

README.md

@@ -2,12 +2,6 @@
   <img src="https://github.com/box/sdks/blob/master/images/box-dev-logo.png" alt= “box-dev-logo” width="30%" height="50%">
 </p>
 
-# Deprecation notice
-
-This version of the Box Java SDK is under maintenance mode, and will be deprecated soon, only critical security updates and bug fixes will be provided. We recommend using the new version Box Java SDK, which can be found at [box/box-java-sdk-gen](https://github.com/box/box-java-sdk-gen)
-
-You can find the migration guide [here](https://github.com/box/box-java-sdk-gen/blob/main/migration-guide.md) for transitioning from Box Java SDK v3.x to the new `box-sdk-gen` package. If you have any questions, please create an issue in the new repository or reach out to [Box Developer Support](https://developer.box.com/support/).
-
 # Migration to v10
 
 The [sdk-gen](https://github.com/box/box-java-sdk/tree/sdk-gen) branch contains the generated code for the `v10` version of the Box Java SDK. This is intended primarily for developers migrating from [Box Java SDK Gen](https://github.com/box/box-java-sdk-gen) to the v10 version.

src/main/java/com/box/sdk/BoxAPIConnection.java

@@ -39,6 +39,7 @@
 /**
  * @deprecated
  * This class, and the com.box.sdk package is deprecated, it is recommended to use com.box.sdkgen package.
+ * Instead of this class use {@link com.box.sdkgen.client.BoxClient}
  *
  * Represents an authenticated connection to the Box API.
  *
@@ -142,6 +143,7 @@ public class BoxAPIConnection {
   /**
    * @deprecated
    * This constructor, and the com.box.sdk package is deprecated, it is recommended to use com.box.sdkgen package.
+   * Instead of this class use {@link com.box.sdkgen.client.BoxClient}
    *
    * Constructs a new BoxAPIConnection that authenticates with a developer or access token.
    *
@@ -155,6 +157,7 @@ public BoxAPIConnection(String accessToken) {
   /**
    * @deprecated
    * This constructor, and the com.box.sdk package is deprecated, it is recommended to use com.box.sdkgen package.
+   * Instead of this class use {@link com.box.sdkgen.client.BoxClient}
    *
    * Constructs a new BoxAPIConnection with an access token that can be refreshed.
    *
@@ -190,6 +193,7 @@ public BoxAPIConnection(
   /**
    * @deprecated
    * This constructor, and the com.box.sdk package is deprecated, it is recommended to use com.box.sdkgen package.
+   * Instead of this class use {@link com.box.sdkgen.client.BoxClient}
    *
    * Constructs a new BoxAPIConnection with an auth code that was obtained from the first half of
    * OAuth.
@@ -207,6 +211,7 @@ public BoxAPIConnection(String clientID, String clientSecret, String authCode) {
   /**
    * @deprecated
    * This constructor, and the com.box.sdk package is deprecated, it is recommended to use com.box.sdkgen package.
+   * Instead of this class use {@link com.box.sdkgen.client.BoxClient}
    *
    * Constructs a new BoxAPIConnection.
    *
@@ -221,6 +226,7 @@ public BoxAPIConnection(String clientID, String clientSecret) {
   /**
    * @deprecated
    * This constructor, and the com.box.sdk package is deprecated, it is recommended to use com.box.sdkgen package.
+   * Instead of this class use {@link com.box.sdkgen.client.BoxClient}
    *
    * Constructs a new BoxAPIConnection leveraging BoxConfig.
    *