JSF primefaces datatable lazy loading multiple selection

i was developing lazy loading dataTable with primeface with pagination.

SelectionMode is multiple.

I was selected 3 check box in first page, now i am go to page 2 and select another 3 check box, now return to page 1. this time check box selection not present in page 1.开发者_JAVA百科

i need to page 1 and 2 selection data. how to get.