判断字符串是否有汉字

//用于判断字符串是否有汉字，有汉字时返回false ，否则为true
public boolean gbk(String str) {

char[] chars = str.toCharArray();
boolean isGB2312 = true;
for (int i = 0; i < chars.length; i++) {
byte[] bytes = ("" + chars[i]).getBytes();
if (bytes.length == 2) {
int[] ints = new int[2];
ints[0] = bytes[0] & 0xff;
ints[1] = bytes[1] & 0xff;
if (ints[0] >= 0x81 && ints[0] <= 0xFE && ints[1] >= 0x40
&& ints[1] <= 0xFE) {
isGB2312 = false;
break;
}
}
}
return isGB2312;
}