Java利用正则表达式统计某个字符串出现的次数

//统计某个字符出现的次数
private void countSubString(){
String string1="香蕉、玉米、面粉";
String string2="香蕉、玉米、面粉";
String string3="牛奶、鸡蛋";
StringBuffer stringBuffer=new StringBuffer();
stringBuffer.append(string1).append("、").append(string2).append("、").append(string3).append("、");
String totalString=stringBuffer.toString();
System.out.println("组拼后的字符串为:"+totalString);
while (totalString.length()>0) {
//得到第一个字符串比如"香蕉、"
int index=totalString.indexOf("、");
String foodName=totalString.substring(0,index+1);
Pattern pattern = Pattern.compile(foodName);
Matcher matcher = pattern.matcher(totalString);
int count=0;
while(matcher.find()){
count++;
}
totalString= totalString.replaceAll(foodName, "");
System.out.println("食品名字为:"+foodName+",出现次数为:"+count);
System.out.println("统计删除后字符串为:totalString="+totalString);
System.out.println("===============================");
}
}