public class Test ...{ public static void main(String[] args) ...{ String str ="aabcwdsfwewefwfewfewewegg"; char[] charArray = str.toCharArray(); System.out.println(charArray.length); int[] count = new int[charArray.length]; for(int i=0;i<charArray.length;i++) ...{ count[i] = 1; for(int j=i+1;j<count.length;j++) ...{ if(charArray[i]==charArray[j]) ...{ count[i] = count[i]+1; } } } for(int i=0;i<count.length;i++) ...{ System.out.print(charArray[i]+" "); int temp = 0; for(int j=0;j<count.length;j++) ...{ if(count[i]<count[j]) ...{ temp++; } } if(temp == 0) ...{ System.out.println(charArray[i]+":"+count[i]); } } }} 另外的方法 import java.util.*;public class MostCharactor ...{ public static void main(String[] args) ...{ String str = "aaaaavvvvvccccccccc"; char[] arr = str.toCharArray(); /**//* TreeMap<Character, Integer> temp = new TreeMap<Character, Integer>(); for (Character x : arr) { Integer time = temp.get(x); if (time == null) time = 1; else time++; temp.put(x, time); } System.out.println(temp.lastKey() + ":" + temp.get(temp.lastKey())); */ Map<Character, Integer> map = new HashMap<Character, Integer>(); int count = 0; int max = 0; char maxChar = 'a'; for (int i = 0; i < arr.length; i++) ...{ if (!map.containsKey(arr[i])) ...{ map.put(arr[i], 1); } else ...{ count = map.get(arr[i]); map.remove(arr[i]); map.put(arr[i], ++count); if (count > max) ...{ max = count; maxChar = arr[i]; } } } System.out.print(maxChar + " "); System.out.println(max); }}