Example
Given a JList like
JList myList = new JList(items);
the selected items in the list can be modified through the ListSelectionModel of the JList:
ListSelectionModel sm = myList.getSelectionModel();
sm.clearSelection(); // clears the selection
sm.setSelectionInterval(index, index); // Sets a selection interval
// (single element, in this case)
Alternatively, JList also provides some convenient methods to directly manipulate the selected indexes:
myList.setSelectionIndex(index); // sets one selected index
// could be used to define the Default Selection
myList.setSelectedIndices(arrayOfIndexes); // sets all indexes contained in
// the array as selected
