通过HTTP服务器发送HTML图像？

Question

I have a java server socket (or http server, everyone calls it something different), and I am trying to display an image. Right now, I am just using an image hosting website, then linking it from there, but I would like to know, if I could send images through my connection? Here is my code, it is only one class,

import java.io.File;
import java.io.IOEXception;
import java.new.ServerSocket;
import java.net.Socket;
import java.util.Scanner
public class main {
public static void main(String argumentsCanBeNamedAnything[]) throws 
IOException {
ServerSocket server = new ServerSocket(80);
System.out.println("Listening");
while(true) {
try(Socket socket = server.accept()) {
String daCode = "";
File file = new File("index.html");
Scanner sc = new Scanner(file);
while(sc.hasNextLine()) {
String i = sc.nextLine();
daCode+=i;
}
String httpResponse = "HTTP/1.1 200 OK\r\n\r\n" + daCode;
socket.getOutputStream().write(httpResponse.getBytes("UTF-8"));
}
}
}
}

I would like to be able to have an image in the same directory as index.html, and then be able to send that image so I don't have to use an image hosting website. Any idea is a good idea :)

Answer 1

You can handle all files with the same piece of code. Once you have an input stream that reads from the file, you should copy all bytes to the socket output stream. So first you should get an input stream like this:

String filename = ...
File file = new File(filename);
InputStream input = new FileInputStream(file);

Then you should get an output stream connected to the socket:

OutputStream output = socket.getOutputStream();

Now you can write the HTTP response like this:

write(output, "HTTP/1.1 200 OK");
write(output, "\n\n");
copyAllBytes(input, output);

The write method would look like this:

void write(OutputStream output, String s) throws IOException {
    output.write(s.getBytes());
}

And the copyAllBytes would look like this:

void copyAllBytes(InputStream input, OutputStream output) throws IOException {
    byte[] buf = new byte[8192];
    int n;
    while ((n = input.read(buf)) != -1) {
        output.write(buf, 0, n);
    }
}

Ideally you should also send a "Content-Type" header that indicates the nature and format of the document. Headers should also be written to the socket output, here is a simple example:

write(output, "HTTP/1.1 200 OK");
write(output, "\n");
write(output, "Content-Type: text/html; charset=utf-8");
write(output, "\n\n");
copyAllBytes(input, output);