JAVA统计字符次数

import java.util.Scanner;

public class tjzfgs {
    public static void main(String[] args) {
        Scanner s=new Scanner(System.in);
        System.out.println("请输入你的字符");
        String line = s.nextLine();

        int daxie=0;
        int xiaoxie=0;
        int shuzi=0;

        for (int i = 0; i = 'A' && ch <= 'Z') {
                daxie++;
            } else if (ch >= 'a' && ch <= 'z') {
                xiaoxie++;
            } else if (ch >= '0' && ch <= '9') {
                shuzi++;
            }
        }
        System.out.println("大写字母"+daxie+"个");
        System.out.println("小写字母"+xiaoxie+"个");
        System.out.println("数字"+shuzi+"个");

    }
}