Is there any java api to change the role or permission for a logged-in user?
One answer
What do you want to achieve and why?
A Custom Condition to Make Attributes Required or Read-Only by Role Version 2 shows API to read the roles. You can also use the API to set the role as described in https://rsjazz.wordpress.com/2013/09/18/deploying-templates-and-creating-projects-using-the-plain-java-clients-library/, however, you must have the permission to do so! If you don't have the JazzAdmin repository role and no permission to save the process, you can't.
You can't break the system and elevate you to an admin.
A Custom Condition to Make Attributes Required or Read-Only by Role Version 2 shows API to read the roles. You can also use the API to set the role as described in https://rsjazz.wordpress.com/2013/09/18/deploying-templates-and-creating-projects-using-the-plain-java-clients-library/, however, you must have the permission to do so! If you don't have the JazzAdmin repository role and no permission to save the process, you can't.
You can't break the system and elevate you to an admin.