java实现统计字符串中字符及子字符串个数的方法示例

import java.util.Scanner;
public class Counter {
  static Scanner scanner = new Scanner(System.in);
  public static void count(String s) {
    int low, upper, num, others;
    low = upper = num = others = 0;
    for (int i = 0; i < s.length(); i++) {
      if (Character.isDigit(s.charAt(i))) {
        num++;
        continue;
      }
      if (Character.isLowerCase(s.charAt(i))) {
        low++;
        continue;
      }
      if (Character.isUpperCase(s.charAt(i))) {
        upper++;
        continue;
      } else {
        others++;
      }
    }
    System.out.println(" 大写字母的个数为：" + upper + "\n 小写字母的个数为：" + low+ "\n 数字的个数为： " + num + "\n 其他字符的个数为： " + others);
  }
  public static void subCounter(String str1, String str2) {
    int counter = 0;
    for (int i = 0; i <= str1.length() - str2.length(); i++) {
      if (str1.substring(i, i + str2.length()).equalsIgnoreCase(str2)) {
        counter++;
      }
    }
    System.out.println("子字符串的个数为： " + counter);
  }
  public static void main(String[] args) {
    // TODO Auto-generated method stub
    System.out.println("请输入一个字符串:");
    String string = scanner.nextLine();
    count(string);
    System.out.println("-----------------------------");
    // 查询在这个字符串中存在多少个子字符串str。
    System.out.println("请输入一个您想查询的子字符串:");
    String str = scanner.nextLine();
    subCounter(string, str);
  }
}