POST call base64 value is too large for an unlimited string in a JSON payload (java.lang.IllegalStateException: Form too large 1555668>200000)?

Hi guys

I have published a post-REST services and receive the pdf as base64 value in an unlimited string attribute of a non-persistent object (as discussed in another forum post).

When sending a small file i can decode the string perfectly to a file, everything works fine.

BUT when the file becomes larger (>2mb) then I get this error:

java.lang.IllegalStateException: Form too large 1555668>200000
	at org.eclipse.jetty.server.Request.extractParameters(Request.java:350)
	at org.eclipse.jetty.server.Request.getParameterNames(Request.java:788)
	at com.mendix.m2ee.appcontainer.server.request.HttpMxRuntimeRequest.parseParameters(HttpMxRuntimeRequest.java:152)
	at com.mendix.m2ee.appcontainer.server.request.HttpMxRuntimeRequest.<init>(HttpMxRuntimeRequest.java:44)
	at com.mendix.m2ee.appcontainer.server.handler.RuntimeHandler.handle(RuntimeHandler.java:41)
	at org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:52)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
	at org.eclipse.jetty.server.Server.handle(Server.java:368)
	at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:489)
	at org.eclipse.jetty.server.AbstractHttpConnection.content(AbstractHttpConnection.java:953)
	at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.content(AbstractHttpConnection.java:1014)
	at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:861)
	at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235)
	at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82)
	at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:628)
	at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:52)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:608)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:543)
	at java.lang.Thread.run(Thread.java:745)

I know that the rest module could receive binary data when the parameter is a filedocument object. But I am wondering how I can receive the full base64 value as a non-filedocument object in an unlimited attribute of a (non) persistent object. Is this possible?