字符串中统计某字母的次数等【Java Base】

【题目】给你一个字符串，包含了空格等标点符号，要你计算出出现次数最多的字母和该字母出现的次数。
【code】：
private static void totalTimes(String str) {
char[] ch = str.toCharArray();
Map<Character, Integer> timesMap = new HashMap<Character, Integer>();

for (int i = 0; i < ch.length; i++) {
if ((ch[i] >= 65 && ch[i] <= 90) || (ch[i] >= 97 && ch[i] <= 122)) {
Integer freq = timesMap.get(ch[i]);
timesMap.put(ch[i], freq == null ? Integer.valueOf(1) : ++freq);
}
}

int charMaxIndex = Collections.max(timesMap.values());
int charMinIndex = Collections.min(timesMap.values());

Set<Character> maxSet = new HashSet<Character>();
Set<Character> minSet = new HashSet<Character>();

for(Map.Entry<Character, Integer> entry : timesMap.entrySet()){

if(entry.getValue().equals(charMaxIndex)){
maxSet.add(entry.getKey());
}

if(entry.getValue().equals(charMinIndex)){
minSet.add(entry.getKey());
}

}

System.out.println("出现最多的字母：" + maxSet);
System.out.println("出现次数:" + charMaxIndex);
System.out.println("出现最小的字母：" + minSet);
System.out.println("出现次数:" + charMinIndex);

}
当然，除了以上，每个人都会有自己心中的code，呵呵！如果不能利用到Java里的集合，那么就可能在数组上做文章了，如下：

String str =  "hello wolrd wlllkdsfhksadfls?sdfls sdf.pqyutgvAAAxzsdfs "  +
               "lsdfj,ljsfd  ajfdsak sfksjdfisfsdkfj lsdfjsidf jsafdalsjfs sfskdfjs" ;
       int [] strCounts =  new   int [ 255 ];
       int  biggestCount =  0 ;
       char  biggestCh =  0 ;
       char  ch =  0 ;
       int  currentCount =  0 ;
       for  ( int  i = str.length() -  1 ; i >=  0 ; i--) {
           ch = str.charAt(i);
           currentCount = ++strCounts[ch];
           if  (currentCount > biggestCount) {
               biggestCount = currentCount;
               biggestCh = ch;
           }
       }
       System.out.println(biggestCh);
       System.out.println(biggestCount);