MTOM error "java.lang.OutOfMemoryError: Java heap space"

[Vikas]

Hi friends,

    I am running sample application "mtom" from standard axis2 samples 
[axis2-1.1.1\samples\mtom]. This sample is working for sending attachment of 
size 2-3 MB, but giving error for more than 3MB size of files.

I want to send file of size 50-100 MB.

error is as follows
     [java] Exception in thread "main" org.apache.axis2.AxisFault: java.lang.Out
OfMemoryError: Java heap space
     [java]     at org.apache.axis2.description.OutInAxisOperationClient.send(Ou
tInAxisOperation.java:271)
     [java]     at org.apache.axis2.description.OutInAxisOperationClient.execute
(OutInAxisOperation.java:202)
     [java]     at sample.mtom.service.MTOMSampleStub.attachment(Unknown Source)

     [java]     at sample.mtom.client.Client.transferFile(Unknown Source)
     [java]     at sample.mtom.client.Client.main(Unknown Source)
     [java] Java Result: 1

I have enabled "MTOM" & "filecaching" both in the client side, but not server 
side caching means in "axis2.xml".
1) Can some one figureout solution?
2) Can we send file as attachment of size 50MB - 1GB?

With best regards
From
Vikas R. Khengare