Create Random Code

Hello,
How can I create a Random Code with Numbers and characters?
I want to save the Code in a String variable.

Niklas

 

Something like this should work if we're thinking along the same page:

Code:java

 
char[] possible = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];
Random r = new Random();
StringBuilder sb = new StringBuilder();
for(int i = 0; i < length; i++){ //length being the code's length
    sb.append(possible[r.nextInt(possible.length)]);
}String code = sb.toString();
 

 

Thank you this was that what I was looking for.

 

If your in need of a unique code guaranteed, you could also create a Hash of the current time. That way you don't accidentally create two identical codes. While it is unlikely that this one will produce two identical codes, it doesn't hurt to be safe.

 

Another thing if the Random r = new Random(); goes into a method and not outside. it will generate the same number every time. (Well that what happened to me while making a plugin)

Code:

private Random r = new Random(); //rnd needs to be here for example
public static void gen(){
//code
}