java随机字符串

public class Random {

	public static void main(String[] args) {
        char cs[] = new char[5];
        for (int i = 0; i < cs.length; i++) {
            while (true) {
                char c = (char) (Math.random() * 125);
                if (Character.isLetter(c) || Character.isDigit(c)) {
                    cs[i] = c;
                    break;
                }
            }
        }
        String result = new String(cs);
        // String result=String.valueof(cs);//正确
        //String result=cs.toString();//错误
        System.out.println(result);
 
    }

最后附上new string、string.valueof、toString与（string）的区别：

toString()、new String()和(String) 、String.ValueOf()的区别