hap: Improve callback registration mechanism

Improves input parameters verification by throwing NPE as requested in
b/218616250. Adjusts the doc accordingly.

Bug: 150670922
Bug: 218616250
Tag: #feature
Test: atest CtsBluetoothTestCases:android.bluetooth.cts.BluetoothHapClientTest
Sponsor: jpawlowski@
Change-Id: I828d578ca53678a2642bc4e73d57b7b481feb88b

1 files changed, 13 insertions, 15 deletions

diff --git a/framework/java/android/bluetooth/BluetoothHapClient.java b/framework/java/android/bluetooth/BluetoothHapClient.java
index fd769d412b..052bd6bfd6 100644
--- a/framework/java/android/bluetooth/BluetoothHapClient.java
+++ b/framework/java/android/bluetooth/BluetoothHapClient.java
@@ -43,6 +43,7 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeoutException;
 
@@ -457,14 +458,16 @@ public final class BluetoothHapClient implements BluetoothProfile, AutoCloseable
      * Register a {@link Callback} that will be invoked during the
      * operation of this profile.
      *
-     * Repeated registration of the same <var>callback</var> object will have no effect after
-     * the first call to this method, even when the <var>executor</var> is different. API caller
-     * would have to call {@link #unregisterCallback(Callback)} with
-     * the same callback object before registering it again.
+     * Repeated registration of the same <var>callback</var> object after the first call to this
+     * method will result with IllegalArgumentException being thrown, even when the
+     * <var>executor</var> is different. API caller would have to call
+     * {@link #unregisterCallback(Callback)} with the same callback object before registering it
+     * again.
      *
      * @param executor an {@link Executor} to execute given callback
      * @param callback user implementation of the {@link Callback}
-     * @throws IllegalArgumentException if a null executor, sink, or callback is given
+     * @throws NullPointerException if a null executor, or callback is given, or
+     *  IllegalArgumentException if the same <var>callback<var> is already registered.
      * @hide
      */
     @SystemApi
@@ -475,12 +478,8 @@ public final class BluetoothHapClient implements BluetoothProfile, AutoCloseable
     })
     public void registerCallback(@NonNull @CallbackExecutor Executor executor,
             @NonNull Callback callback) {
-        if (executor == null) {
-            throw new IllegalArgumentException("executor cannot be null");
-        }
-        if (callback == null) {
-            throw new IllegalArgumentException("callback cannot be null");
-        }
+        Objects.requireNonNull(executor, "executor cannot be null");
+        Objects.requireNonNull(callback, "callback cannot be null");
         if (!isEnabled()) {
             throw new IllegalStateException("service not enabled");
         }
@@ -521,7 +520,8 @@ public final class BluetoothHapClient implements BluetoothProfile, AutoCloseable
      * <p>Callbacks are automatically unregistered when application process goes away
      *
      * @param callback user implementation of the {@link Callback}
-     * @throws IllegalArgumentException when callback is null or when no callback is registered
+     * @throws NullPointerException when callback is null or IllegalArgumentException when no
+     *  callback is registered
      * @hide
      */
     @SystemApi
@@ -531,9 +531,7 @@ public final class BluetoothHapClient implements BluetoothProfile, AutoCloseable
             android.Manifest.permission.BLUETOOTH_PRIVILEGED,
     })
     public void unregisterCallback(@NonNull Callback callback) {
-        if (callback == null) {
-            throw new IllegalArgumentException("callback cannot be null");
-        }
+        Objects.requireNonNull(callback, "callback cannot be null");
 
         if (DBG) log("unregisterCallback");