NullPointerException in restartLoader Method of LoaderManager

Question

I have the following own Interface Implementation in my Fragment: ``` @Override public void onReportChanged(Fragment sender, long id, int position) { // Views ein und ausblenden _List.setVisibility(View.GONE); _OnLoading.setVisibility(View.VISIBLE); _NoDataView.setVisibility(View.GONE); _ReportId = id; getLoaderManager().restartLoader(_LM_REPORTS, null, this); }; ``` The FragmentActivity report to this Fragment, that another Fragment (Selection List) have selected one item. After that the ListFragment should load new Data with reported ID (_ReportId). But I get `NullPoinerException` on this code before going to onCreateLoader-Method. Here is the LogCat: ``` 05-28 14:24:37.905: E/AndroidRuntime(1775): FATAL EXCEPTION: main 05-28 14:24:37.905: E/AndroidRuntime(1775): java.lang.NullPointerException 05-28 14:24:37.905: E/AndroidRuntime(1775): at android.support.v4.app.LoaderManagerImpl.restartLoader(LoaderManager.java:637) 05-28 14:24:37.905: E/AndroidRuntime(1775): at de.webducer.android…

Accepted Answer

I found the reason:

```
@Override
public Loader<Cursor> onCreateLoader(int id, Bundle extra) {
    CursorLoader returnValue = null;
    if (_ReportId > 0) {
        switch (id) {
            case _LM_REPORTS:
                returnValue = new CursorLoader(getActivity(),
                    ReportContentProvider.CONTENT_URI_REPORT_DATA,
                    null,
                    ReportTable.COLUMN_ID + " =?",
                    new String[] { String.valueOf(_ReportId) },
                    null);
                    break;

default:
                    break;
            }
        }
    return returnValue;
}
```

The Loader have allways to run. The condition `if (_ReportId > 1)` produced the exception. Without the condition the code runs fine.

NullPointerException in restartLoader Method of LoaderManager

Solution

Problem