Java：如何根据非字母定界符反转字符串？

如何基于非字母定界符反转字符串？我怀疑我的正则表达式可能是问题。

String fileContent = "Joe'); MAKE TEST random;--";
String[] splitWords = fileContent.split("[^a-zA-Z0-9']+");

StringBuilder stringBuilder = new StringBuilder();
for (String word : splitWords) {
    int idx = fileContent.indexOf(word, stringBuilder.length());
    String delim = fileContent.substring(stringBuilder.length(), idx);
    stringBuilder.append(delim);

    StringBuilder output = new StringBuilder(word).reverse();
    stringBuilder.append(output);
}
return stringBuilder.toString();

Current output: 'eoJ); EKAM TSET modnar

Desired output: eoJ'); EKAM TSET modnar;--