Java在不同的行上写入相同的txt文件

Question

I dont have any worthwhile code to show but I am trying to understand the concept.

I am opening a text file in two classes, one time saves a username like "user242," and the other class saves a number "42421,". The way I have set this out it saves on different lines such as:

line: 1 - user242, line: 2 -42421,

But every time I run the classes again it doesnt go in the format: line: 1 - user242, user114, line: 2 - 42421, 42525

It instead messes up and goes:

line: 1 - user242, line: 2 - 42421, user114, line: 3 - 4252

I think this is because of my use in newLine(); so is this any way I can fix this so it writes one variable always to the top line and the second always to the second line?

Answer 1

you can't insert data into a file. you can overwrite data using RandomAccessFile though. open the file, read the contents, modify and write them back.

you can also look at this Tutorial