package *.collections;//包名

import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class HomeWork5 {
        //5.键盘输入字符串，去重，并且保证顺序一致
        public static void main(String[] args) {

                //输入字符串
                Scanner scanner = new Scanner(System.in);
                System.out.println("请输入字符：");
                String string = scanner.next();
                char[] chars = string.toCharArray();
                Set<Character> set = new HashSet<>();
                for (int i =0;i < chars.length;i++){

                        set.add(chars[i]);
                }
                System.out.println(set);
        }
}

结果：