GUID UUID

• http://betterexplained.com/articles/the-quick-guide-to-guids/
• RFC 4122

In Java

• http://stackoverflow.com/questions/2982748/create-a-guid-in-java
• http://stackoverflow.com/questions/3388085/how-to-create-guid-in-java-ee
• http://www.javapractices.com/topic/TopicAction.do?Id=56
• http://kodejava.org/how-do-i-generate-uuid-guid-in-java/

import java.util.UUID;

UUID uuid = UUID.randomUUID();
String randomUUIDString = uuid.toString();

import java.util.UUID;

public class GenerateUUID {
  public static final void main(String... aArgs){
    //generate random UUIDs
    UUID idOne = UUID.randomUUID();
    UUID idTwo = UUID.randomUUID();
    log("UUID One: " + idOne);
    log("UUID Two: " + idTwo);
  }

  private static void log(Object aObject){
    System.out.println( String.valueOf(aObject) );
  }
} 

import java.util.UUID;

public class RandomStringUUID {
    public static void main(String[] args) {
        //
        // Creating a random UUID (Universally unique identifier).
        //
        UUID uuid = UUID.randomUUID();
        String randomUUIDString = uuid.toString();

        System.out.println("Random UUID String = " + randomUUIDString);
        System.out.println("UUID version       = " + uuid.version());
        System.out.println("UUID variant       = " + uuid.variant());
    }
}

Concerns

• Is it slow?