Setting a JList items to match a source list

jlistSelection.java

// myJList => JList component holding type MyObject
// sourceList => List<MyObject> (or other colleciton type) to match selection

// note MyObject will be checked for referential == if you do not implement equals and hashCode

var model = (DefaultListModel<MyObject>) myJList.getModel();
myJList.clearSelection();
int[] indexes = sourceList.stream()
       .mapToInt(obj -> model.indexOf(obj))
       .filter(idx -> idx >= 0).toArray();
myJList.setSelectedIndices(indexes);