Reputation: 39
I've been trying to do a list out of an images from the assets directory, and this is my code
ArrayList<Bitmap> list = new ArrayList<>();
try{
String[] PathFiles = assetManager.list("img");
for (int i = 0; i < PathFiles.length; i++) {
InputStream is = assetManager.open("img/" + PathFiles[i]);
Bitmap bitmap = BitmapFactory.decodeStream(is);
list.add(i, bitmap);
}
}
catch(IOException e)
{
e.printStackTrace();
}
But when ever this code is executed, my app crashes. What would be the problem?
logcat of the app :
10-29 18:19:06.712 18272-18272/com.example.mohammed.myapplication E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.mohammed.myapplication, PID: 18272
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.mohammed.myapplication/com.example.mohammed.myapplication.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String[] android.content.res.AssetManager.list(java.lang.String)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2790)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2855)
at android.app.ActivityThread.access$900(ActivityThread.java:181)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1474)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:6117)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String[] android.content.res.AssetManager.list(java.lang.String)' on a null object reference
at com.example.mohammed.myapplication.MainActivity.onCreate(MainActivity.java:49)
at android.app.Activity.performCreate(Activity.java:6374)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2743)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2855)
at android.app.ActivityThread.access$900(ActivityThread.java:181)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1474)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:6117)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
Upvotes: 0
Views: 1223
Reputation: 5261
you need to initialise your array list first
ArrayList<Bitmap> list=new ArrayList<>();
Upvotes: 1
Reputation: 12523
I would say you get a NullPointerException
here:
list.add(i, bitmap);
you dont create the ArrayList
:
ArrayList<Bitmap> list;
try it with:
ArrayList<Bitmap> list = new ArrayList<>;
Upvotes: 1