Delete data from a file

Question

Hi,
I would like to know , how can I delete a line from a text_file,
and when it is deleted, I don�t want that there is a gap between
lines.
Could it be possible to use class RandomAccessFile to do it?
Please help me.
thanks.

Answer 1

You could do it with a BufferedReader. But there's no way to just magically delete the line. No matter what method you use, you'll have to:
1) Read all the data in the file up to but not including the line, then write it to the new file.
2) Skip the line you want to delete.
3) Read all of the data in the file starting after the line you want to delete going to the end of the file, then write that to the new file as well.
That's pretty general. Those steps could change if you, say, want the input and output file to be the same (in that case, you could just seek to the end of the line and move all the data after the line back to close the gap, then truncate the end of the file off), or if you are implementing stuff a bit different (for example, reading all the lines into a list, removing the lines from the list, and writing them back to a file).
Jason