密码合格验证程序

package HUAWEI;

import java.util.Scanner;

public class Main1_1 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        StringBuilder builder = new StringBuilder();
        while (scanner.hasNext()) {
            String input = scanner.nextLine();
            System.out.println(passwordValidate(input));
        }
        scanner.close();
 
    }
 
    private static String passwordValidate(String input) {
        final String OK = "OK";
        final String NG = "NG";
 
        // 长度超过8
        if (input == null || input.length() < 9) {
            return NG;
        }
 
        int num1 = 0,num2 = 0,num3 = 0,num4 = 0;
        
 
        // 统计
        for (int i = 0; i < input.length(); i++) {
            char ch = input.charAt(i);
            if (ch >= 'A' && ch <= 'Z') {
                num1 = 1;
            } else if (ch >= 'a' && ch <= 'z') {
                num2 = 1;
            } else if (ch >= '0' && ch <= '9') {
                num3 = 1;
            } else {
                num4 = 1;
            }
        }
          
        // 小于三种
        if ((num1 + num2 + num3 + num4) < 3) {
            return NG;
        }
 
        System.out.println("字符串的长度："+input.length());
        for (int i = 0; i < input.length() - 3; i++) {
            String s1 = input.substring(i, i + 3);
            String s2 = input.substring(i + 3, input.length());
            System.out.println("第"+i+"次"+s1+"..."+s2);
            if (s2.contains(s1)) {
                return NG;
            }
        }
        return OK;
    }
}