查询字符串中字母，数字，空格出现的次数

Java代码   

public static void main(String[] args)
{
    BufferedReader bfr = new BufferedReader(new FileReader("d:\1.txt"));
    StringBuffer sbf = new StringBuffer();
    String line;
    int character = 0,digital = 0, blank = 0, other = 0;
    while((line = bfr.readLine()) != null)
    {
         sbf.append(line+"\r\n");
    }
    String str = sbf.toString();
    char[] arr = str.toCharArray();
    for(char c : arr)
    {
        if((c >= 'a' && a <= 'z') || (c >= 'A' && c <= 'Z'))
        {
            character++;
        }
        else if(c >= '0' || c <= '9')
        {
            digital = 0;
        }
        else if(c == ' ')
        {
            blank++;
        }
        else
        {
            other++;
        }
        System.out.println("输入的符串为:"+str);
        System.out.println("总共字符数目为"+str.length());
        System.out.println("字母数目"+character);
        System.out.println("数字数目"+digital);
        System.out.println("空格数目"+blank);
        System.out.println("其他字符数目"+other);
    }
}