Java Data Type - 如何在java中查找字符串的所有大写字母

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
  public static void main(String args[]) throws IOException {
    String data, answer = "";
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    System.out.println("Enter any String : ");
    data = br.readLine();
    char[] findupper = data.toCharArray();
    for (int i = 0; i < findupper.length; i++) {
      if (findupper[i] >= 65 && findupper[i] <= 91) // ascii value in between 65
                                                    // and 91 is A to Z
      {
        answer += findupper[i]; // adding only uppercase
      }
    }
    System.out.println("Answer : " + answer);
  }
}