Java

Java RSS

Deleting contents of a file before writing

Please support our Java advertiser: Programming Forums - DaniWeb Sister Site

•

Join Date: Sep 2007

Posts: 2

Reputation: Joaoalex7 is an unknown quantity at this point

Solved Threads: 0

Joaoalex7

Offline

Newbie Poster

Deleting contents of a file before writing

Dec 27th, 2008

Hello

I'm having some trouble writing to text and object files in java. Basically i need to delete the contents of the file before i write the new information on it...which i'm not being able to do.

well this is what i have in terms of code for the text file:

 Help with Code Tags 
 java Syntax (Toggle Plain Text) 
try
{
	fW = new BufferedWriter(new FileWriter("Pedidos_Formacao.txt"));
	fW.write("Pedido");
	fW.newLine();
        fW.close;
}
try
{
	fW = new BufferedWriter(new FileWriter("Pedidos_Formacao.txt"));
	fW.write("Pedido");
	fW.newLine();
        fW.close;
}

and this is for the object file:

 Help with Code Tags 
 java Syntax (Toggle Plain Text) 
try
{
	os = new ObjectOutputStream(new FileOutputStream("Utilizadores.bin"));
        User x = new User("João",1);
	os.writeObject(x);
}
try
{
	os = new ObjectOutputStream(new FileOutputStream("Utilizadores.bin"));
        User x = new User("João",1);
	os.writeObject(x);
}

I have no problem writing but i need to delete the contents of the file before doing so or else this code will simply add the new information to the one that was already in the file.
Can anyone help me?

Thanks in advance

João

•

Join Date: Nov 2007

Posts: 121

Reputation: puneetkay is on a distinguished road

Solved Threads: 23

puneetkay

Offline

Junior Poster

Re: Deleting contents of a file before writing

-1

Dec 27th, 2008

Hello,

Well this code will overwrite the data in file. You don't need to delete content of files before adding new information.

Also, i just tried both codes. Working perfectly! and data in both files were overwrote.

Best of luck!

Last edited by puneetkay; Dec 27th, 2008 at 2:56 pm.

Puneet Kalra
www.PuneetK.com
Sun Certified Java Programmer

Admin of Pikk - Object Relational Mapping Framework

•

Join Date: Sep 2008

Posts: 1,598

Reputation: BestJewSinceJC is a name known to all

Solved Threads: 202

BestJewSinceJC BestJewSinceJC is offline

Offline

Posting Virtuoso

Re: Deleting contents of a file before writing

Dec 27th, 2008

I would imagine that Puneetkay is correct since this is what I know from experience. But if you want to explicitly delete the file, use the File class.

http://java.sun.com/j2se/1.4.2/docs/...a/io/File.html

File myFile = new File("fileName.txt");
myFile.delete();