top row
SIZE space rows
bottom row

=====================================
  
for (int i = 1; i <= SIZE + 2; i++)
     print("*")
println()
for (int i = 1; i <= SIZE; i++)
  space row
for (int i = 1; i <= SIZE + 2; i++)
     print("*")
println()
  
===========================================
  
for (i = 1; i <= SIZE + 2; i++)
     print("*");
println()
for (int i = 1; i <= SIZE; i++)
  print("*")
  print SIZE spaces
  println("*")
for (int i = 1; i <= SIZE + 2; i++)
     print("*")
println()
  
===============================================
  
for (int i = 1; i <= SIZE + 2; i++)
     print("*");
println()
for (int i = 1; i <= SIZE; i++)
  print("*")
  for (int j = 1; j <= SIZE; j++)
     print(" ")
  println("*")
for (int i = 1; i <= SIZE + 2; i++)
     print("*")
println()