Sort list of strings as BigDecimal in reverse order in Java

I need to sort list of strings comparing them as BigDecimal. Here is what I tried:

List<String> sortedStrings = strings
    .stream()
    .sorted(Comparator.reverseOrder(Comparator.comparing(s -> new BigDecimal(s))))
    .collect(Collectors.toList());

List<String> sortedStrings = strings
    .stream()
    .sorted(Comparator.reverseOrder(Comparator.comparing(BigDecimal::new)))
    .collect(Collectors.toList());

List<String> sortedStrings = strings
    .stream()
    .sorted(Comparator.comparing(BigDecimal::new).reversed())
    .collect(Collectors.toList());

Can I somehow do this without explicitly specifying the types?

Answer

You can do it like this.

List<String> strings = List.of("123.33", "332.33");
List<String> sortedStrings = strings
        .stream()
        .sorted(Comparator.comparing(BigDecimal::new, Comparator.reverseOrder()))
        .collect(Collectors.toList());

System.out.println(sortedStrings);

prints

[332.33, 123.33]

You could also do it like this but need to declare the type parameter as a String.

List<String> sortedStrings = strings
        .stream()
        .sorted(Comparator.comparing((String p)->new BigDecimal(p)).reversed())
        .collect(Collectors.toList());

But here is the way I would recommend doing it. BigDecimal implements the Comparable interface. So you simply map all the values to BigDecimal, sort them in reverse order, and then convert back to a String. Otherwise, the other solutions will continue to instantiate a BigDecimal object just for sorting and that could result in many instantiations.

List<String> sortedStrings = strings
        .stream()
        .map(BigDecimal::new)
        .sorted(Comparator.reverseOrder())
        .map(BigDecimal::toString)
        .collect(Collectors.toList());

System.out.println(sortedStrings);