Caught a RuntimeException from the binder stub implementation when swap data in arrayadapter

Question

public class MainActivity extends AppCompatActivity {       ArrayList<String> list = new ArrayList<>();       ArrayAdapter<String> adapter;       ArrayList<String> data1 = new ArrayList<>();       ArrayList<String> data2 = new ArrayList<>();  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);      for (int i = 0 ; i< 10 ;i++){         data1.add(String.valueOf(i));     }      for (int i = 20; i < 30; i++){         data2.add(String.valueOf(i));     }      Spinner spinner = (Spinner) findViewById(R.id.demo);     adapter = new ArrayAdapter<>(this,android.R.layout.simple_dropdown_item_1line,list);     spinner.setAdapter(adapter); }  private void change(boolean which){     if (which){         list.clear();         list.addAll(data1);      }else{         list.clear();         list.addAll(data2);      }     adapter.notifyDataSetChanged(); }  @Override public boolean onCreateOptionsMenu(Menu menu) {     // Inflate the menu; this adds items to the action bar if it is present.     getMenuInflater().inflate(R.menu.menu_main, menu);     return true; }  @Override public boolean onOptionsItemSelected(MenuItem item) {     // Handle action bar item clicks here. The action bar will     // automatically handle clicks on the Home/Up button, so long     // as you specify a parent activity in AndroidManifest.xml.     int id = item.getItemId();      //noinspection SimplifiableIfStatement     if (id == R.id.action_no) {         change(true);         return true;     }else if (id == R.id.action_ok){         change(false);         return true;     }      return super.onOptionsItemSelected(item); }   } 

when I swap the data in the spinner , there is a error :

08-25 11:51:59.630   29087-9866/me.aber.app.arrayapdapterdemo D/dalvikvm? GC_FOR_ALLOC freed 2055K, 52% free 7378K/15192K, paused 24ms, total 30ms 08-25 11:52:01.923   29087-9866/me.aber.app.arrayapdapterdemo W/Binder? Caught a RuntimeException from the binder stub implementation.     java.lang.NullPointerException at android.view.WindowManagerGlobal.dumpGfxInfo(WindowManagerGlobal.java:437) at android.app.ActivityThread$ApplicationThread.dumpGfxInfo(ActivityThread.java:1021) at android.app.ApplicationThreadNative.onTransact(ApplicationThreadNative.java:550) at android.os.Binder.execTransact(Binder.java:404) at dalvik.system.NativeStart.run(Native Method) 

This appears randomly as I click the action.

Answer 1

W/Binder? Caught a RuntimeException from the binder stub implementation. java.lang.NullPointerException 

The message starts with W/, which means its just a warning. So you can ignore it. Its Android's internal ignorable issue.

This may be the source of the warning: https://android.googlesource.com/platform/frameworks/base.git/+/master/core/java/android/os/Binder.java#1054

If your code works correctly then you should ignore these warnings.