Setting Custom HTTP Header for GWT Forms

Question

How can I set additional HTTP headers while submitting forms with GWT.
(I am using FormPanel for building the form)

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Summary

From accepted answer:

HTTP headers cannot be set using FormPanel - FormPanel wraps the standard HTML <form>, which doesn't allow setting custom headers.

Answer 1

HTTP headers cannot be set using FormPanel - FormPanel wraps the standard HTML <form>, which doesn't allow setting custom headers.

To set your own headers use a RequestBuilder:

RequestBuilder rb = new RequestBuilder(Method.POST, "http://www.my-server.com");
rb.setHeader("X-My-Header", "VALUE");
Request r = rb.sendRequest(null, new RequestCallback() {...});