random - How to randomly select 7 letters(a to z ) in java -

i want select 7 random letters z

so far have found ways select single letter https://stackoverflow.com/a/5202888/3209901

random r = new random(); char c = (char) (r.nextint(26) + 'a'); 

why 7 letters because , need apply conditions 7 letters - check words formed 7 letters , word length should minimum of 4 letters ......

here's java-8 solution:

new random().ints('a', 'z'+1).distinct()             .limit(7).foreach(ch -> system.out.println((char)ch));