How to generate random UUID in Java

Hi there! Generating a random UUID is much more easier than you could ever imagine! I use the following block of code, whenever I’m in a need of more than ten:

for(int i = 0; i < 30; i++) {

If things get difficult and time passes, working with UUIDs, you ‘ll probably get lost, if the way you chose to generate your UUID was “a bunch at a time”, like above, so you could either visit a site, like this or modify your program like below:




How to fix Java heap space error in Maven

So you want to build a maven project but you ‘re getting an error like this : java.lang.OutOfMemoryError: PermGen space.

What the output says is that you have to define a MAVEN_OPTS environment variable, where you can place your -Xmx and -XX:MaxPermSize memory parameters.

What are you staring at? Go for it!

  • Right click on My Computer and select Properties
  • Click Advanced System Settings on the left
  • Go to the Advanced tab, click the Environment Variables
  • Create a New user variable, under the name of to MAVEN_OPTS and set the Variable value to what the error specified or whatever you need to get it build successfully.

  • Here’s a sample configuration :