Server side HTTP Post using JSP
Ok, so I use a rapid application development technology (ColdFusion or PHP) most of the time because customers demand such quick turnaround. This time I needed to go back to goold old Java and do some integration.
Our email list management service (Sound-Off 3) manages people's email lists and lets them schedule mailings, etc. I needed to integrate a website build on JRun (using Java Server Pages aka jsp) so that when people register, it relays the info to Sound-Off 3.
In ColdFusion, you can easily do this with a CFHTTP tag. In JSP it is a little more involved. My struggle is your benefit, b/c here is the code that does it in JSP.
This code will do an HTTP POST from the WEB SERVER to the remote site, all behind the scenes on the server. The "parameters" string contains the form values that will be sent to the remove server. Note the leading/trailing &'s and that the form values must be URL encoded.
try
{
String stuff = null;
String pagecontent = "";
String parameters = "&message=hello+world&";
java.net.URL url = new java.net.URL(http://www.yourhost.com/page.cfm);
java.net.HttpURLConnection conn = (java.net.HttpURLConnection)url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Length", "" + Integer.toString(parameters.getBytes().length));
conn.setRequestProperty("Content-Language", "en-US");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setAllowUserInteraction(true);
java.io.DataOutputStream printout = new java.io.DataOutputStream (conn.getOutputStream ());
printout.writeBytes (parameters);
printout.flush ();
printout.close ();
java.io.BufferedReader in = new java.io.BufferedReader(new java.io.InputStreamReader(conn.getInputStream()));
while ((stuff = in.readLine()) != null)
{
pagecontent += stuff;
}
in.close();
%>success! <%
}
catch (Exception e)
{
%>error!<%
}
%>
And thats it! You can (and should) do further error checking by examinging the contents of "pagecontent" which will have the html code returned from remote website.
Have fun...
