How can I fix the method merge to have the output in order .??? please explain with comments

/// code

public class Test implements Sorter{

@Override

public > List sort(List list) {

// TODO Auto-generated method stub

List newList = new ArrayList(list);

return mySort(newList);

}

protected static > List mySort(List list){

if(list.size()

List firstHalf = list.subList(0 , list.size()/2);

firstHalf.sort(Comparator.naturalOrder());

// mySort(firstHalf);

// System.out.println();

// System.out.println(firstHalf);

List secondHalf = list.subList(list.size()/2, list.size());

secondHalf.sort(Comparator.naturalOrder());

// mySort(secondHalf);

// System.out.println();

// System.out.println(secondHalf);

merge(firstHalf, secondHalf, list);

return list; // sorted list.

}

/**

* merges and sorts two pieces of list.

* @param firstHalf the first half of the list.

* @param secondHalf the second half of the list.

* @param sortedList the sorted list

* @param generic type T

* @return

*/

protected static > List

merge(List firstHalf, List secondHalf, List sortedList)

{

int index1 = 0;

int index2 = 0;

int sortedIndex = 0;

if (firstHalf.isEmpty()) {

return secondHalf;

}

else if (secondHalf.isEmpty()) {

return firstHalf;

}

else {

while(index1

if(firstHalf.get(index1).compareTo(secondHalf.get(index2))

sortedList.set(sortedIndex++, firstHalf.get(index1++));

else

sortedList.set(sortedIndex++ ,secondHalf.get(index2++));

}

System.out.println();

System.out.println(sortedList);

}

return sortedList;

}

public static void main(String[] args) {

// TODO Auto-generated method stub

Test data1 = new Test();

List list = new ArrayList();

list.add( 3);

list.add( 5);

list.add( 1);

list.add( 9);

list.add( 7);

list.add( 4);

list.add( 2);

list.stream();

System.out.print("List before Sorting ... ");

System.out.println();

for(Integer c : list) System.out.print(c + " ");

System.out.println();

System.out.println();

System.out.print("List after Sorting ... ");

data1.sort(list);

}

}

public class Test implements Sorter{ @Override public > List sort(List list) { // TODO Auto-generated method stub List newList = new ArrayList (list); return mySort(newList); } protected static > List mySort(List list){ if(list.size() firstHalf = list.subList(0, list.size()/2); firstHalf.sort(Comparator.naturalOrder()); mySort(firstHalf); System.out.println(); System.out.println(firstHalf); List secondHalf = list. subList(list.size()/2, list.size()); secondHalf.sort(Comparator.naturalOrder()); mySort (secondHalf); System.out.println(); System.out.println(secondHalf); merge(firstHalf, secondHalf, list); return list; // sorted list. } protected static > List merge(List firstHalf, List secondHalf, List sortedlist) { int index1 = 0; int index2 = 0; int sortedIndex = 0; if (firstHalf.isEmpty()) { return secondHalf; } else if (secondHalf.isEmpty()) { return firstHalf; } else { while(index1 void main(String[] args) { // TODO Auto-generated method stub Test datal = new Test(); List list = new ArrayList(); list.add( 3); list.add( 5); list.add( 1); list.add( 9); list.add( 7); list.add( 4); list.add( 2); list.stream(); for(Integer c: list) System.out.print(c + " "); //System.out.print("/"); data1.sort(list); } } List before Sorting 3 5 1 9 7 4 2 List after Sorting [1, 2, 2, 2, 4, 7, 9]