Convert Array to string in Java/Groovy

Question

I have a list like this:

List tripIds = new ArrayList()  def sql = Sql.newInstance("jdbc:mysql://localhost:3306/steer", "root", "", "com.mysql.jdbc.Driver")          sql.eachRow("SELECT trip.id from trip JOIN department WHERE organization_id = trip.client_id AND department.id = 1") {   println "Gromit likes ${it.id}"   tripIds << it.id }  

On printing tripids gives me value:

  [1,2,3,4,5,6,] 

I want to convert this list to simple string like:

 1,2,3,4,5,6 

How can I do this?

Answer 1

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(", ") 

Answer 2

In groovy:

def myList = [1,2,3,4,5] def asString = myList.join(", ")