Java后端是怎么返回一个网页的？

一、直接上代码

    public static void main(String[] args) {
        try {
            ServerSocket server = new ServerSocket(9999) ;
            Socket socket = server.accept();

            //读取数据
            InputStream inputStream = socket.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
            String value = bufferedReader.readLine();
            System.out.println(value);

            //返回网页
            OutputStream outputStream = socket.getOutputStream();
            PrintWriter out = new PrintWriter(outputStream);

            out.write("HTTP1.1 200 OK\r\n");
            out.write("Content-Type:text/html;charset=UTF-8\r\n");
            out.write("\r\n");
            out.write("<html>");
            out.write("<body>");
            out.write("<input type='text' placeholder='aaaaaaaa' />");
            out.write("<button>22222</button>");
            out.write("</body>");
            out.write("</html>");
            out.flush();

        }catch (Exception e) {
            e.printStackTrace();
        }
    }

二、效果展示