java - Avoiding duplicate values in the datatable -

java - Avoiding duplicate values in the datatable -

i have list of product info in datatable1 , list of selected product info in datatable2 (which user has selected datatable1 , add together dattable2) want perform 1 check if user selected datatable1 add together & if same info exists in list should not added list of datatable 2 friend suggested use

hashmap<string ,list<model>>

is improve approach accomplish functionality ? thanks

if can utilize java.util.set implementations rather list, build duplicate-free list of model follows:

set<model> datatable1 = ... set<model> datatable2 = ... datatable2.addall(datatable1);

datatable2 contain either in datatable1 or datatable2, no duplicates (set union operation).

be sure implement appropriate equals , hashcode on model class.

java jsf-2 richfaces