关于Java求助

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
String[] num;//声明一个数组来保存你输入的字符中的所有数值型值
String strs = "";
int temp = 0;
System.out.println("请输入一段字符串:");// fdf12.6df51fdf2
String s = input.next();
for (int i = 0; i < s.length(); i++) {
char str = s.charAt(i);
if (str >= '0' && str <= '9' || str == '.') {
strs += str;
temp = 0;
} else if (temp == 0) {
strs += " ";
temp = 1;
}
}
strs = strs.trim();//去掉前后空格
num = strs.split(" ");//以空格来截取数值型值并保存到数组中
double sum = 0;
double[] st = new double[num.length];//声明一个double型数组来保存原字符数组元素
for (int i = 0; i < num.length; i++) {
//把数组中的字符型都转换成double型
st[i] = Double.parseDouble(num[i].toString());
}
for (int i = 0; i < st.length; i++) {
sum += st