I used to use this software back in 2014 in second year of my degree college. actually even that time Eclipse was way better then netbeans but we had to use this as it was mentioned in practical journal. it gives limited options and is relatively slow.
Now a days it is not used too much as visual studio has taken over everything. auto code completion was good but thats something almost every IDE offers now a days. if you wants to go for java specific IDE then I would suggest Eclipse.