java实现统计字符串中大写字母，小写字母及数字出现次数的方法示例

public class TestSubstring {  public static void main(String[] args) {    getCount("adsJKJ3K21AfaAD134F13241d134134s141faAAFDF");  }  //统计字符串中，大写字母，小写字母，数字出现的次数  public static void getCount(String str) {    int upper = 0;    int lower = 0;    int digi = 0;    for (int i = 0, len = str.length(); i < len; i++) {      char c = str.charAt(i);      if (c >= 'A' && c <= 'Z') {        upper++;      } else if (c >= 'a' && c <= 'z') {        lower++;      } else if (c >= '0' && c <= '9') {        digi++;      }    }    System.out.println("大写字母:" + upper); //大写字母:13    System.out.println("小写字母:" + lower); //小写字母:9    System.out.println("数字:" + digi);   //数字:20  }}