Question

I am fetching data from a database using this code :

Cursor cursor = db.query(News_Table, null, null, null, null, null, null);

if (cursor != null) 
{
    cursor.moveToFirst();
}
allNews = new News[cursor.getCount()];
int i = 0;

while (!(cursor.isLast())) 
{
    allNews[i] = new News(cursor.getInt(0), cursor.getString(2),
            cursor.getString(1));
    cursor.moveToNext();
    i++;
}    

This is how my table looks :

But everytime my last row is not being fetched and i get a null pointer exception. Here is the log cat screen :

Why is my code running only for n-1 rows correctly and giving a problem on the (n)th row, where n is the total number of rows in my news table.

Answer 1

cursor.isLast() will return true when the cursor is on the last row, and so your while loop will stop at that point having not read & processed the last row. typically the pattern for iterating a cursor would be (note this doesn’t call moveToFirst() either)

Cursor cursor = getACursor();
int i = 0;
while (cursor.moveToNext()) {
   /// do something with this row
   allNews[i] = new News(cursor.getInt(0), cursor.getString(2),cursor.getString(1));
   i++;
}