输出一个字符串中出现次数最多的字符

package demo;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

public class MaxEng {
public static void main(String[] args) {
Map<String, Integer> map = new HashMap<>();
String s ="aaabbcccaccbbbbb";
String str = "";
int count = 0;
for (int i = 0; i < s.length(); i++) {
str = String.valueOf(s.charAt(i));
if (map.get(str) == null) {
count = 0;
} else {
// count ++; //这时他会按顺序依次累加，不会识别key的值
count = map.get(str);// 防止他重复累加
}
map.put(str, ++count);// 先加1再计数，不然会少加一次
}
/*
* for (Object string : map.keySet()) { System.out.println(string
* +"======"+ map.get(string)); }
*/
// 遍历一遍，找出最大值
Integer maxValue = 0;
String Key = "";

Set<String> keySet = map.keySet();
Iterator<String> it = keySet.iterator();

while (it.hasNext()) {
String keyit = it.next();
Integer value = map.get(keyit);

if (value > maxValue) {
maxValue = value;
Key = keyit;
}
}
System.out.println("输出最多的字符为" + Key + "次数为" + maxValue);
}
}