Output values found in cursor to logcat? - Android

Question

I'm trying to debug an issue myself. May post it later if I fail ;-)

My logcat log states "android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 2"

I would like to use log.v("desc", cursor) to show what the cursor returns. Is there a way to specify a value from it like cursor[0] ?

Infrastructure

"I would like to use log.v("desc", cursor) to show what the cursor returns. Is there a way to specify a value from it like cursor[0] ?" I wonder what you mean in the sentence? Would you like to see whole row number 0 (value of all columns in row 0)? – Indre

Answer 1

You should call moveToFirst() on Cursor.

Indre

Answer 2

Android has provided a specific class just for debugging Cursors. It is called DatabaseUtils.

Call the method dumpCursorToString() to view the contents of your cursor.

This helper loops through and prints out the content of the Cursor for you, and returns the cursor to its original position so that it doesn't mess up your iterating logic.

Colorific

Answer 3

use this before cursor.moveToFirst()

Log.v("Cursor Object", DatabaseUtils.dumpCursorToString(cursor))

Overseer

+ import android.database.DatabaseUtils; – Witwatersrand

Answer 4

If you intend to write contents of the cursor to the logcat row by row you can use code as below:

if (cursor.moveToFirst()) {
    do {
        StringBuilder sb = new StringBuilder();
        int columnsQty = cursor.getColumnCount();
        for (int idx=0; idx<columnsQty; ++idx) {
            sb.append(cursor.getString(idx));
            if (idx < columnsQty - 1)
                sb.append("; ");
        }
        Log.v(TAG, String.format("Row: %d, Values: %s", cursor.getPosition(), 
            sb.toString()));
    } while (cursor.moveToNext());
}

Indre

what if column is not string, it may be int double? – Phyllisphylloclade

Answer 5

Or if you're looking for where the cursor is at a specific point in time, call Cursor.getPosition()

Take a look at the Cursor API.

It's often very wordy, but sometimes it helps.

Bullhorn