Java: Reverse string via a delimiter

Question

I am trying to reverse the characters in a string separated by a delimiter I provide.

Input: string: "Abc.134dsq" , delimiter: "."

Desired Output: cbA.qsd431

My attempt:

String fileContent = "Abc.134dsq";
String delimiter = ".";
fileContent = fileContent.replace(delimiter, "-");
String[] splitWords = fileContent.split("-");
StringBuilder stringBuilder = new StringBuilder();
for (String word : splitWords) {
    StringBuilder output = new StringBuilder(word).reverse();
    stringBuilder.append(output);
}

System.out.println(stringBuilder.toString());

Answer 1

Try this:

System.out.println(Arrays
    .stream("Abc.134dsq".split("\.", -1))
    .map(StringBuilder::new)
    .map(StringBuilder::reverse)
    .collect(Collectors.joining(".")));

See live demo.

This handles the “preserving the trailing dot” scenarios mentioned in the comments. Live demo shows this aspect too.

Enough time has passed that your homework deadline has passed, so I thought I’d show you this one-liner.