make a backup copy using JFileChooser

Question

I need to make a backup copy of a selectedfile, while using JfileChooser so that the user can specify/or select the name for the back up file. I have to use DataInputStream and DataOutputStream and the readByte and writeByte methods for this process.

Here is what i have so far:

public class BasicFile {        

    public BasicFile() throws FileNotFoundException, IOException{
        JFileChooser chooser = new JFileChooser();
        chooser.showOpenDialog(null);
        File f = chooser.getSelectedFile();            
        if (f.isFile()) 
        {
           DataInputStream dis = new DataInputStream(new FileInputStream(f));
        }
    }        
}

so basically you want to read one file and copy the contents to another file, yes? There is a load of samples you could google for. — Matthias, Oct 25 '13 at 06:42
yes sir, ive tried googling, im not exactly sure how to go about it really. — Manu, Oct 25 '13 at 06:45
Have a look here on how to copy files in a lot of different ways: http://stackoverflow.com/questions/2520305/java-io-to-copy-one-file-to-another I do not understand why you have to use `DataInputStream` and `DataOutputStream` for this, but they are working like the other Streams. — Matthias, Oct 25 '13 at 06:52
i have to use both those classes for this particular project im working on. But thank you for the help! — Manu, Oct 25 '13 at 07:00

Akkusativobjekt · Accepted Answer · 2013-10-25T07:12:46.723

Solution with both streams :

        DataInputStream dis = new DataInputStream(new FileInputStream(f));
        ByteArrayOutputStream buffer = new ByteArrayOutputStream();

        int nRead;
        byte[] data = new byte[dis.available()];

        while ((nRead = dis.read(data, 0, data.length)) != -1) {
            buffer.write(data, 0, nRead);
        }

        buffer.flush();

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutputStream dataOutStream = new DataOutputStream(baos);
        dataOutStream.write(data);

        OutputStream outputStream = new FileOutputStream("newFilePath");
        baos.writeTo(outputStream);
        baos.close(); //Lets close some streams 
        dataOutStream.close();
        outputStream.close();
        buffer.close();
        dis.close();

Maybe there is a shorter solution, bute the code aboves works.

Without requirement it would be just one line with the Files.copy method.

Files.copy(f.toPath(),new File("newFilePath").toPath(), StandardCopyOption.REPLACE_EXISTING);

Thank you! but i need to understand how to incorporate datainputstream and dataoutputstream with this — Manu, Oct 25 '13 at 06:53
If it it's the correct solution for your problem, mark the answer as accepeted, that other users can notice it easily. — Akkusativobjekt, Oct 25 '13 at 07:25

make a backup copy using JFileChooser

1 Answers1