Communication between two portals:JSP

We have two java portals,say portal A and portal B

Portal A has some button called "communicate" .When we press it,portal A should contact portal B and portal B should then send a file to po开发者_Python百科rtal A as a reply.

The file is not a static file.The file should be generated according to the values that portal A has sent.ie every time when a request is fired a file is generated afresh and sent back to portal A.

Can anyone explain how to do this in java?..

Thanks in advance..

You can write some servlet in portal B. And call that servlet from portal A. You can send values to servlet.