copying contents of one file to another

[linus dale]

this program takes name of a file as command line argument
and copies contents of that file to a newly created file called newfile.txt

newfile.txt is formed but nothing is written to it

and if newfile.txt already exists,and has something in it,it becomes empty
why is this happening?

import java.io.*;

public  class  File3
{

public static void main(String args[])throws IOException
{
int len;
File f3=new File(args[0]);

InputStream binputStream= new FileInputStream(f3);



OutputStream bout=new FileOutputStream("newfile.txt");

byte buf[]=new byte[1024];


System.out.println("length  of  buf  is "+buf.length);
System.out.println("len  is  "+len);

while((len=binputStream.read(buf))>=0)
{System.out.println("len  is  "+len);

System.out.println("length  of  buf  is "+buf.length);
bout.write(buf,0,len);
System.out.println("length  of  buf  is "+buf.length);
System.out.println("len  is  "+len);
}

System.out.println("length  of  buf  is "+buf.length);
System.out.println("len  is  "+len);
bout.close();
binputStream.close();
System.out.println("file created.....");
}

}

please help
thanks

[Campbell Ritchie]

Please go through the Java™ tutorials section about I/O and have a look at the documentation in the API for FileOutputStream. I thought a FileOutoutStream was not suitable for .txt files, and you should use a FileWriter instead. But I am not up to speed about byte[] arrays, I am afraid; somebody else may have a better idea.

[linus dale]

Campbell Ritchie wrote:Please go through the Java™ tutorials section about I/O and have a look at the documentation in the API for FileOutputStream. I thought a FileOutoutStream was not suitable for .txt files, and you should use a FileWriter instead. But I am not up to speed about byte[] arrays, I am afraid; somebody else may have a better idea.

I got it
it was because I had 2 files called File3.java in different folders

i was making changes in the wrong file

[Rob Spoor]

Campbell Ritchie wrote:I thought a FileOutoutStream was not suitable for .txt files, and you should use a FileWriter instead.

If you want to treat the contents as characters inside your Java code, then you're right. But for copying, FileInputStream is just fine. After all, the contents of any file is still in bytes, even if it does represent text. The bytes are simply copied, so the destination will still be the same as the source.

[Campbell Ritchie]

Thanks, Rob