Java Image Server：套接字写入错误

Question

A couple of days ago I thought about programming my own image client to transfer images directly via the HTTP. I googled and researched quite some time and wrote my server:

public class SConnection extends Thread {

    Socket client;

    /* ... */

    @Override
    public void run() {

        while(true) {
            try {

                //Get some image paths
                File folder = new File(new java.net.URI("file:///C:/images/"));
                File[] images = folder.listFiles();
                //Load the image
                BufferedImage bi = ImageIO.read(images[0]);
                //Write the image
                ImageIO.write(bi, "JPEG", client.getOutputStream());

            } catch (Exception ex) {

                ex.printStackTrace();
                return;

            }

        }

    }

The main class is a Thread waiting to accept many connections, storing them in an ArrayList, creating instances of SConnection and starting them.

The client looks like this:

URL target = new URL("http://127.0.0.1:82"); //The server - so far, so good
URLConnection conn = target.openConnection();
BufferedImage in = ImageIO.read(conn.getInputStream()); //And as I try to receive the image: boom, exception
File save = new File(new java.net.URI("file:///C:/images/result.jpeg"));
ImageIO.write(in, "JPEG", save);

Server and client both send Exceptions located at the ImageIO.write / ImageIO.read - lines.

The server says:

java.net.SocketException: Connection reset by peer: socket write error

The client says:

java.io.IOException: Invalid Http response

I get, that the image is not transferred correctly, but what should I change? Any clues?

Thanks you guys, in advance!

Answer 1

1. You don't appear to be writing HTTP headers, so the client URLConnection won't understand the reply and will close the connection, causing 'connection reset by peer' at the sender.

2. You don't need to construct a URI to open a file.

3. You don't need to use ImageIO at all. This just wastes time and space. Just copy the bytes, like any other file type.

In short you don't really need this code at all. The default servlet will do it for you.