How do I save images downloaded from the Internet?

Question

I have the URL to an image stored on the Internet. Is it possible to open a connection and store the image on my computer? I'm not totally new to this, I've written a small program that could read text files from an ftp server, but it's my first try at downloadning images. Here's the code I'm using
String wwwfile = ....;
               System.out.println(protocol+host+wwwfile);
                    URL url = new URL(protocol+host+wwwfile);
                    URLConnection urlc = url.openConnection();
                    InputStreamReader reader = new InputStreamReader(urlc.getInputStream());
                    File file = new File(path,fileName);
                    OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(file));
                    int c;
                    while((c = reader.read())!=-1)
                    writer.write(c);
                    reader.close();
                    writer.flush();
                    writer.close();
When I read text files, I used BufferedReader/PrintWriter instead of InputStreamReader/OutputStreamReader. The picture I want to download seems to be downloaded, it's stored on the computer, but upon viewing the picture, the browser displays the icon telling me the picture is abscent.
What is it that I'm doing wrong?
regards
simon

Answer 1

Ah, this might be the problem. You're using an InputStreamReader and OutputStreamWriter to wrap the streams with reader/writers. This is bad. This will corrupt binary data.
Try this:
        System.out.println(protocol + host + wwwfile);
        URL url = new URL(protocol + host + wwwfile);
        URLConnection urlc = url.openConnection();
        // Use InputStream/OutputStreams instead of Reader/Writers for binary data.
        // Otherwise it will get corrupted.
        InputStream in = urlc.getInputStream();
        File file = new File(path, fileName);
        OutputStream out = new BufferedOutputStream(new FileOutputStream(file));
        int c;
        while ((c = in.read()) != -1) {
            out.write(c);
        in.close();
        // You don't have to flush the file if you're
        // closing it right after.
        out.close();