Question

I wrote this program to copy one pdf file to other but I’m getting curupt fiel in o/p for .txt files this code is working fine.

code:

public class FileCopy {

    public static void main(String args[]) {

        try {
            FileInputStream fs = new FileInputStream("C:\\dev1.pdf");
            byte b;
            FileOutputStream os = new FileOutputStream("C:\\dev2.pdf");
            while ((b = (byte) fs.read()) != -1) {
                os.write(b);
            }
            os.close();
            fs.close();
        } catch (Exception E) {
            E.printStackTrace();
        }
    }
}

Answer 1

It’s because you are mixing ints and bytes. This should work as expected:

int b;
while ((b = fs.read()) != -1) {
    os.write(b);
}

In particular, when fs.read() returns 255, (byte) fs.read returns -1.