StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POnullpointerexception and i dont know why
text
Body
copied!<p>I get the following error:</p> <pre><code>06-09 06:56:24.675: E/AndroidRuntime(1629): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.gauvion.simpleworkouttracker/com.myapp.MainActivity}: java.lang.NullPointerException </code></pre> <p>Logcat says its caused by:</p> <pre><code>06-09 06:56:24.675: E/AndroidRuntime(1629): Caused by: java.lang.NullPointerException 06-09 06:56:24.675: E/AndroidRuntime(1629): at com.myapp.MainActivity.onCreate(MainActivity.java:26) </code></pre> <p>Here is the code for MainActivity:</p> <pre><code>package com.myapp; import android.app.ListActivity; import android.database.Cursor; import android.os.Bundle; import android.support.v4.widget.SimpleCursorAdapter; import android.view.Menu; import android.widget.Toast; public class MainActivity extends ListActivity { private DayDataSource datasource; private SimpleCursorAdapter dataAdapter; private Cursor cursor; private boolean isEditing = false; private Toast toast_deleted; private String[] columns = new String[] { MySQLiteHelper.COLUMN_NAME, MySQLiteHelper.COLUMN_DAY }; private int[] to; @SuppressWarnings("deprecation") @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); cursor = datasource.fetchAllDays(); startManagingCursor(cursor); to = new int[] { R.id.listitem_day_name, R.id.listitem_day_day }; dataAdapter = new SimpleCursorAdapter(this, R.layout.listitem_day, cursor, columns, to, 0); setListAdapter(dataAdapter); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.activity_main, menu); return true; } } </code></pre> <p>Here's the code for DayDataSource:</p> <pre><code>package com.myapp; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.util.Log; public class DayDataSource { private SQLiteDatabase database; private MySQLiteHelper dbHelper; public DayDataSource(Context context) { dbHelper = new MySQLiteHelper(context); } public void open() throws SQLException { database = dbHelper.getWritableDatabase(); } public void close() { dbHelper.close(); } public void createDay(String name, String day) { ContentValues values = new ContentValues(); values.put(MySQLiteHelper.COLUMN_NAME, name); values.put(MySQLiteHelper.COLUMN_DAY, day); database.insert(MySQLiteHelper.TABLE_DAYS, null, values); } public void updateDay(long id, String name, String day) { ContentValues values = new ContentValues(); values.put(MySQLiteHelper.COLUMN_NAME, name); values.put(MySQLiteHelper.COLUMN_DAY, day); database.update(MySQLiteHelper.TABLE_DAYS, values, MySQLiteHelper.COLUMN_ID + " = " + id, null); } public void deleteDay(long id) { database.delete(MySQLiteHelper.TABLE_DAYS, MySQLiteHelper.COLUMN_ID + " = " + id, null); } public Cursor fetchAllDays() { Cursor cursor = database.rawQuery("select " + MySQLiteHelper.COLUMN_ID + ", " + MySQLiteHelper.COLUMN_NAME + ", " + MySQLiteHelper.COLUMN_DAY + " " + "from " + MySQLiteHelper.TABLE_DAYS + " " + "order by case " + MySQLiteHelper.COLUMN_DAY + " " + "when 'Monday' then 0 " + "when 'Tuesday' then 1 " + "when 'Wednesday' then 2 " + "when 'Thursday' then 3 " + "when 'Friday' then 4 " + "when 'Saturday' then 5 " + "when 'Sunday' then 6 " + "when 'No Specific Day' then 7 " + "end", null); if (cursor != null) { cursor.moveToFirst(); } return cursor; } } </code></pre> <p>Any help would be greatly appreciated.</p>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload