Java Data Type - 如何反转字符串中的每个单词而不改变它们的位置

public class Main {
  public static void main(String args[]) {
    String input = "this is a test";
    String[] words = input.split(" ");
    String reverse = "";
    for (int i = 0; i < words.length; i++) {
      for (int j = words[i].length() - 1; j >= 0; j--) {
        reverse += words[i].charAt(j);
      }
      System.out.print(reverse + " ");
      reverse = "";
    }
  }
}