Java Remote Method Invocation: 10

Java Remote Method Invocation

10.4 RMI's Use of HTTP POST Protocol

In order to invoke remote methods through a firewall, some RMI calls make use of the HTTP protocol, more specifically HTTP POST. The URL specified in the post header can be one of the following:

http://<host>:<port>/
http://<host>:80/cgi-bin/java-rmi?forward=<port>

The first URL is used for direct communication with an RMI server on the specific host and port. The second URL form is used to invoke a "cgi" script on the server which forwards the invocation to the server on the specified port.

An HttpPostHeader is a standard HTTP header for a POST request. An HttpResponseHeader is a standard HTTP response to a post. If the response status code is not 200, then it is assumed that there is no Return. Note that only a single RMI call is embedded in an HTTP POST request.

HttpMessage:: HttpPostHeader Header Message
HttpReturn:: HttpResponseHeader Return

Note - Only the SingleOpProtocol appears in the Header of an HttpMessage. An HttpReturn does not contain a protocol acknowledgment byte.

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