You should use the URLConnection object in the applet, and you open a url
socket to the servlet, then in the servlet use the ServletOutputStream in
order to send your DataOutputStream that is prepared in servlet.
Look at the following code fragments...
----This is servlet side code: in this code a DataOutputStream is created
from ByteArrayOutputStream and its is sent by ServletOutputStream as byte
array----
public void doPost(HttpServletRequest req,
HttpServletResponse resp)
throws ServletException, java.io.IOException
{
// if you want to read data from applet, DataInputStream is created
from request's getInputStream
// Get the input stream for reading data from the client
DataInputStream in =
new DataInputStream(req.getInputStream());
// Read the some string
String s1 = in.readUTF();
String s2 = in.readUTF();
// We'll be sending binary data back to the client so
// set the content type appropriately
resp.setContentType("application/octet-stream");
// Data will always be written to a byte array buffer so
// that we can tell the client the length of the data
ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
// Create the output stream to be used to write the
// data to our buffer
DataOutputStream out = new DataOutputStream(byteOut);
out.writeUTF("some sring");
...... //write all parameters into DataOutputStream "out"
// Flush the contents of the output stream to the
// byte array
out.flush();
// Get the buffer that is holding our response
byte[] buf = byteOut.toByteArray();
// Notify the client how much data is being sent
resp.setContentLength(buf.length);
// Send the buffer to the client
ServletOutputStream servletOut = resp.getOutputStream();
// Wrap up
servletOut.write(buf);
servletOut.close();
}
----Here is the applet side code: first create an URL connection to the
servlet and then write or read data from stream---
protected void sendSomeData()
throws Exception
{
// Get the server URL
java.net.URL url = new java.net.URL(codeBase + servlet);
// Attempt to connect to the host
java.net.URLConnection con = url.openConnection();
// Initialize the connection
con.setUseCaches(false);
con.setDoOutput(true);
con.setDoInput(true);
// these parts are to send data to the server, the preparing byte
array procedure is the same with servlet counterpart.
// Data will always be written to a byte array buffer so
// that we can tell the server the length of the data
ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
// Create the output stream to be used to write the
// data to our buffer
DataOutputStream out = new DataOutputStream(byteOut);
// Send some string
out.writeUTF(s1);
out.writeUTF(s2);
// Flush the data to the buffer
out.flush();
// Get our buffer to be sent
byte buf[] = byteOut.toByteArray();
// Set the content that we are sending
con.setRequestProperty("Content-type",
"application/octet-stream");
// Set the length of the data buffer we are sending
con.setRequestProperty("Content-length",
"" + buf.length);
// Get the output stream to the server and send our
// data buffer
DataOutputStream dataOut =
new DataOutputStream(con.getOutputStream());
dataOut.write(buf);
// Flush the output stream and close it
dataOut.flush();
dataOut.close();
// these parts are for reading data from servlet
// Get the input stream we can use to read the response
DataInputStream in =
new DataInputStream(con.getInputStream());
// Read the response from the server, the order of read must be same
the
// order of write that was done in servlet. and the read type is also
important
someString = in.readUTF();
// Close the input stream
in.close();
}
----------------------------------------------------------------------------
------------------------
if you have difficulties with using streams, please let me know...
Deniz...
----- Original Message -----
From: "dushyanth harinath" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, October 09, 2000 5:00 PM
Subject: servlet-applet communication
> Hi folks,
> I want to invoke an applet from a servlet and send
> 10/15 parameters to it which i retreive from the
> database using a servlet.How should i go about
> acheiving this.
> Any help will be greatly appreciated
> thanks
> dushyanth
>
> =====
> H.Dushyanth
> Programmer
> Archean Infotech Limited
> http://www.archeanit.com
> Where Technology Meets Business
>
> ____________________________________________________________
> Do You Yahoo!?
> Get your free @yahoo.co.in address at http://mail.yahoo.co.in
>
>
___________________________________________________________________________
> To unsubscribe, send email to [EMAIL PROTECTED] and include in the
body
> of the message "signoff SERVLET-INTEREST".
>
> Archives: http://archives.java.sun.com/archives/servlet-interest.html
> Resources: http://java.sun.com/products/servlet/external-resources.html
> LISTSERV Help: http://www.lsoft.com/manuals/user/user.html
___________________________________________________________________________
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff SERVLET-INTEREST".
Archives: http://archives.java.sun.com/archives/servlet-interest.html
Resources: http://java.sun.com/products/servlet/external-resources.html
LISTSERV Help: http://www.lsoft.com/manuals/user/user.html
