What's the best way to trim() all elements in a List<String>? [duplicate]

Question

I have a List<String>, potentially holding thousands of strings. I am implementing a validation method, which includes ensuring that there aren't any leading or trailing whitespaces in each string.

I'm currently iterating over the list, calling String.trim() for each String, and adding it to a new List<String> and reassigning back to the original list after:

List<String> trimmedStrings = new ArrayList<String)();
for(String s : originalStrings) {
  trimmedStrings.add(s.trim());
}

originalStrings = trimmedStrings;

I feel like there's a DRYer way to do this. Are there alternate, more efficient approaches here? Thanks!

Edit: Yes I am on Java 8, so Java 8 suggestions are welcome!

Answer 1

In Java 8, you should use something like:

List<String> trimmedStrings = 
    originalStrings.stream().map(String::trim).collect(Collectors.toList());

also it is possible to use unary String::trim operator for elements of the initial list (untrimmed String instances will be overwritten) by calling this method:

originalStrings.replaceAll(String::trim);

Answer 2

If you are on java-8, you can use :

    final List<Object> result = arrayList.stream()
        .map(String::trim)
        .collect(Collectors.toList());