parse the xml and display the content in a viewer

Hi,
When the xml packet comes in though a network ,how would i parse it 
first and then display the data. The data would be mostly in images so 
it would be displayed in a customized viewer written in java .I would 
like to know how would this be implemented . As far as my understanding 
i would need something which is good at streaming application. That is 
beacuse i would have to process the data as it comes in .
Thanks
Jay