java code

hello everyone

i have a form inside it there is a select box allow multiple value name and id = approversList

and also have a hidden field at the same form with a default value name and id = firstApproverSelected

i want to call the approversList and firstApproverSelected inside tool process (in java code) 

how can i called them ? 

note : i initialize them in workflow variable as well 

so i want to take approversList list and store the first value inside the firstApproverSelected 

how to call them and update the firstApproverSelected value with the first value from approversList ? 

if you can write the whole code i will be super thankful