Prevent use of NFC api if device is not featurized for NFC.

Change-Id: I8724cb947223b7b60814d0be51e1122123ebb98a
Signed-off-by: Nick Pelly <npelly@google.com>

1 files changed, 31 insertions, 1 deletions

diff --git a/core/java/android/nfc/NfcAdapter.java b/core/java/android/nfc/NfcAdapter.java
index 6f718d3..d76ac41 100644
--- a/core/java/android/nfc/NfcAdapter.java
+++ b/core/java/android/nfc/NfcAdapter.java
@@ -15,7 +15,10 @@ import java.lang.UnsupportedOperationException;
 
 import android.annotation.SdkConstant;
 import android.annotation.SdkConstant.SdkConstantType;
+import android.app.ActivityThread;
 import android.content.Context;
+import android.content.pm.IPackageManager;
+import android.content.pm.PackageManager;
 import android.nfc.INfcAdapter;
 import android.os.IBinder;
 import android.os.RemoteException;
@@ -152,6 +155,26 @@ public final class NfcAdapter {
     }
 
     /**
+     * Helper to check if this device has FEATURE_NFC, but without using
+     * a context.
+     * Equivalent to
+     * context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_NFC)
+     */
+    private static boolean hasNfcFeature() {
+        IPackageManager pm = ActivityThread.getPackageManager();
+        if (pm == null) {
+            Log.e(TAG, "Cannot get package manager, assuming no NFC feature");
+            return false;
+        }
+        try {
+            return pm.hasSystemFeature(PackageManager.FEATURE_NFC);
+        } catch (RemoteException e) {
+            Log.e(TAG, "Package manager query failed, assuming no NFC feature", e);
+            return false;
+        }
+    }
+
+    /**
      * Get a handle to the default NFC Adapter on this Android device.
      * <p>
      * Most Android devices will only have one NFC Adapter (NFC Controller).
@@ -165,9 +188,16 @@ public final class NfcAdapter {
             }
             sIsInitialized = true;
 
+            /* is this device meant to have NFC */
+            if (!hasNfcFeature()) {
+                Log.v(TAG, "this device does not have NFC support");
+                return null;
+            }
+
+            /* get a handle to NFC service */
             IBinder b = ServiceManager.getService("nfc");
             if (b == null) {
-                Log.d(TAG, "NFC Service not available");
+                Log.e(TAG, "could not retrieve NFC service");
                 return null;
             }