public void go()
{
    ArrayList<String> fruits = new ArrayList<>();

    fruits.add("pear");
    fruits.add("pineapple");
    fruits.add("oranges");
    fruits.add("banana");
    fruits.add("apple");

    for(String str: fruits)
    {
         if(str.contains("apple"))
         {   /* I would like anything containing 'apple'
          * i.e. apple & pineapple to be placed on top of the array*/   }
    }
    for(String str: fruits)
    {
        System.out.println(str);
    }
}

List<String> apples = new ArrayList<>();
List<String> nonApples = new ArrayList<>();
for (String fruit : fruits) {
  if (fruit.contains("apple")) {
    apples.add(fruit);
  } else {
    nonApples.add(fruit);
  }
}
Collections.sort(apples);
apples.addAll(nonApples);
// apples now contains what you want. Of course, it's now misnamed :)

List<String> result = new ArrayList<>(apples);
Collections.sort(result);
result.addAll(nonApples);

for (int i = 0; i < result.size(); i++) {
  fruits.set(i, result.get(i));
}

Collections.sort(fruits, new Comparator<String>(){

        @Override
        public int compare(String arg0, String arg1) {
            if (arg0.contains("apple") && arg1.contains("apple")) {
                return arg0.compareTo(arg1);
            }
            else if (arg0.contains("apple") && !arg1.contains("apple")){
                return -1;
            }
            else if (!arg0.contains("apple") && arg1.contains("apple")){
                return 1;
            } else return 0;
        } });

public class AppleStringComparator implements Comparator<String> {

    @Override
    public int compare(String o1, String o2) {
        if (o1.contains("apple")) {
            if (o2.contains("apple")) {
                return o1.compareTo(o2);
            } else {
                return -1;
            }
        } else {
            if (o2.contains("apple")) {
                return 1;
            } else {
                return 0;
            }
        }
    }
}

public class MainClass {
    public void go() {
        // The example code from the OP
        ArrayList<String> fruits = new ArrayList<>();

        fruits.add("pear");
        fruits.add("pineapple");
        fruits.add("oranges");
        fruits.add("banana");
        fruits.add("apple");

        Collections.sort(fruits, new AppleStringComparator());

        // Print out the result, for completeness' sake:
        System.out.println(fruits);
}

List<String> containingApple = new ArrayList<>();
for (String s : list) {
    if (s.contains("apple")) {
        containingApple.add(s);
    }
}
Collections.sort(containingApple);
List<String> result = new ArrayList<>(list.size());
result.addAll(containingApple);
for (String s : list) {
    if (!s.contains("apple")) {
        result.add(s);
    }
}