显示串中只出现一次的字符.

public static void firstNoRepeatingChar(String str) {
char[] strArr = str.toCharArray();
Map<Character, Integer> mapc = new HashMap<Character, Integer>();
for (char c : strArr) {
if (mapc.get(c) == null) {
mapc.put(c, 1);
} else {
mapc.put(c, mapc.get(c) + 1);
}
}

Set<Character> sc = mapc.keySet();
for (char c : sc) {
if (mapc.get(c) == 1) {
System.out.println(c);
break;
}
}

int[] strArr1 = new int[256];
for(char c : strArr){
strArr1[c]++;
}

for(int i = 0; i < 256; i++){
if(strArr1[i] == 1){
System.out.println((char)i);
break;
}
}
}