Convert Array to string in Java/Groovy
Use join, e.g.,
tripIds.join(", ")Unrelated, but if you just want to create a list of something from another list, you'd be better off doing something like a map or collect instead of manually creating a list and appending to it, which is less idiomatic, e.g. (untested),
def sql = Sql.newInstance("jdbc:mysql://localhost:3306/steer", "root", "", "com.mysql.jdbc.Driver")def tripIds = sql.map { it.id }Or if you only care about the resulting string,
def tripIds = sql.map { it.id }.join(", ")
Use the join method that Groovy addes to Collection
List l = [1,2,3,4,5,6]assert l.join(',') == "1,2,3,4,5,6"