Looking for id/key generator

[Igor]

Hi all,

I am looking for an ID/key generator in Java. It can be a class or a
package.
I need the result to be something like 2AF33Y88 - digits and letters
together.
It can be fixed size or I have to set the length.

Thanks in advance,
Igor

 

[Roy Epperson]

Here's a portion of a class I wrote to generate keys. I also have a method
to reject offensive words and fragments of words and a method that look into
a table of already generated keys to insure the new key is unique. Let me
know privately if you're interested in those.

private static final String characterMap =
"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

public static String[] generate(int randomStringLength, int
numberOfStrings, Random random){
String ans[] = new String[numberOfStrings];
for(int x= 0; x < numberOfStrings; x++){
StringBuffer sb = new StringBuffer();
for(int n = 0; n <randomStringLength; n++){
sb.append(characterMap.charAt(random.nextInt(61)));
}
ans[x] = sb.toString();
}
return ans;
}

 

[Johann Burkard]

Igor wrote:

[Please set a Followup-To when posting to multiple groups]

I am looking for an ID/key generator in Java. It can be a class or a
package.
I need the result to be something like 2AF33Y88 - digits and letters
together.

If you need unique keys, I implemented the UUID/GUID specification once,
it's at http://johannburkard.de/misc/uuid.zip.

If you need "safe" passwords, check out
http://johannburkard.de/misc/PasswordTools.java.

Johann

 

[Steve Horsley]

One question.

What if you need not duplicated ids?
Is it enought if you use both timestamp + thread_id ?

Thank you.

Can you be sure the same thread won't hand out 2 nummbers within one
clock-tick (55mS on Win95)?

How about a class that hands out incrementing int values (let it wrap) and
concatenate that int value with the current time. You are unlikely to dish
out 4 billion IDs within 55mS.

Steve