How to generate 8 character long alphanumeric string

[Basit56]

Hi,
Hope you all will be fine.I want to generate 8 character long alphanumeric string and for this i used this line of code

 System.out.println(Long.toHexString(Double.doubleToLongBits(Math.random())));

But the problem is this gives me 16 character long string how can i reduce it to 8 characters, please help

Thank you

[r035198x]

But you won't get all the alphanumerics with that.
Better have a look at

                String alphaNumerics = "qwertyuiopasdfghjklzxcvbnm1234567890";
		String t = "";
		for (int i = 0; i < 8; i++) {
			t += alphaNumerics.charAt((int) (Math.random() * alphaNumerics.length()));
		}
		System.out.println(t);

[Basit56]

Hi :),
Thank you very much. You post a nice code because it's very very simple and up to my expectations, but i found this code, it's also very easy. I am posting it here so others can also look at it if they want to like it.

public class AlphaNumeric {
    
    private static final String ALPHA_NUM ="0123456789abcdef";

    public static String getAlphaNumeric(int len) {
        StringBuffer sb = new StringBuffer(len);
        for (int i=0; i<len; i++) {
            int ndx = (int)(Math.random()*ALPHA_NUM.length());
            sb.append(ALPHA_NUM.charAt(ndx));
        }
        return sb.toString();
        }

    public static void main(String[] args) {
            
        System.out.println(" character long: " +getAlphaNumeric(8));
      
        /** 
         * Another method
        String alphaNumerics = "qwertyuiopasdfghjklzxcvbnm1234567890";
        String t = "";
        for (int i = 0; i < 8; i++) {
            t += alphaNumerics.charAt((int) (Math.random() * alphaNumerics.length()));
        }
        System.out.println("with new code: " + t);
         */
    }
}

Thank you:)

[r035198x]

If you want to use a buffer for the result then use StringBuilder instead of StringBuffer.
StringBuilder is faster.

[mtyoung]

StringBuilder and StringBuffer are the same, except StringBuffer is thread safe.