Well, more than a question this is an answer, I was trying to see for Glassfish 4.0 default admin password to access its console but I didn't find any satisfactory answer, some suggested to change admin-keyfile on glasssfish folder which can also work... anyhow... here it is how I did it...
well, it turns out that it HAS a default password in the most recent version of netbeans, I discover that it is self-generated and it's not generic, to see your password go to services tab and then right click on your glassfish 4.0 server, then choose properties and then you'll see your password stored there on the common tab, click on show and you'll have your password...
hope to help you guys!
[root@ip-172-31-20-218 bin]# ./asadmin change-admin-password Enter admin user name [default: admin]>admin Enter the admin password>**[Note: as default password for admin in Glassfish 4.0 is blank, you need to press enter key only. Do not type any thing.]** Enter the new admin password> Enter the new admin password again> Command change-admin-password executed successfully.