参考原文地址:https://www.cnblogs.com/zwwhnly/p/12449818.html
public static void main(String[] args) {
//被统计的字符串
String str = "ABC123ABC";
//查找的字符
String searchChar = "B";
int count = 0;
//原来的字符串的长度
int origialLength = str.length();
//将字符串中的指定字符去掉
str = str.replace(searchChar, "");
//去掉指定字符的字符串长度
int newLength = str.length();
//指定字符出现的次数
count = origialLength - newLength;
System.out.println("字符" + searchChar + "出现的次数为:" + count);
}
