From last time, I had told how to encode image into base64 string[1], and how to do POST message to HTTP server[2][3] This post will continue from those posts. First, we will create HTTP POST server in Python. I based on the concept that a message will be encoded using url-encode format in a form of base64 string, and the image string will be sent to a variable named "img". It will decode an image string from that variable.
import SimpleHTTPServer
import SocketServer
import cgi
from base64 import decodestring
PORT = 8000
class ServerHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
def _writeheaders(self):
self.send_response(200)
self.send_header('Content-type', 'text/html')
self.end_headers()
def do_GET(self):
filename = 'temp.png'
f = open(filename, 'rb')
encode = f.read().encode('base64')
img = '<img height="200" src="data:image/png;base64,' + encode + '" width="250" />'
self._writeheaders()
self.wfile.write("""
<html><head><title>Simple Server</title></head>
<body>
It worked!!!!
%s
</body>
</html>""" % (img))
def do_POST(self):
form = cgi.FieldStorage(
fp=self.rfile,
headers=self.headers,
environ={'REQUEST_METHOD':'POST',
'CONTENT_TYPE':self.headers['Content-Type'],
})
encode = form['img'].value
decode = decodestring(encode)
output = open('temp.png', 'wb')
output.write(decode)
output.close()
# After posting image has done, it will response GET message to show that image
self.do_GET()
Handler = ServerHandler
httpd = SocketServer.TCPServer(("", PORT), Handler)
print "serving at port", PORT
httpd.serve_forever()
Then, we will create HTTP POST client to upload an image to our HTTP POST server.
Python:
import urllib, urllib2
uri = 'http://localhost:8000'
filename = 'Leafa.jpg'
f = open(filename, 'rb')
encode = f.read().encode('base64')
params = { 'img' : encode }
data = urllib.urlencode(params)
p = urllib2.urlopen(uri, data)
print p.read()
C# WPF:
string fileName = "Leafa.jpg";
StreamResourceInfo sri = null;
Uri uri = new Uri(fileName, UriKind.Relative);
sri = Application.GetResourceStream(uri);
using (var memoryStream = new MemoryStream())
{
sri.Stream.CopyTo(memoryStream);
byte[] result = memoryStream.ToArray();
var base64 = "img=" + HttpUtility.UrlEncode(System.Convert.ToBase64String(result));
MessageBox.Show(base64);
using (var wc = new WebClient())
{
wc.Headers["Content-Type"] = "application/x-www-form-urlencoded";
wc.UploadStringCompleted += wc_UploadStringCompleted;
wc.UploadStringAsync(new Uri(url), "POST", base64);
}
}
The server will response a web page, which the client will show that response as a text format, so, if you want to make sure that your image are already uploaded, just check it the "server.py" directory. You will see the image named "temp.png", which is converted from jpg image in the client side. Moreover, you can use a web browser request to http://localhost:8000 to let GET response show you that uploaded one.
References:
The sample project is uploaded, can download from http://www.mediafire.com/?1okv3lc6nk1jsc7.
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| Leafa.jpg |
