Swift. Can`t save file to DocumentDirectory. Whats wrong? - swift2

Question

Here`s my code:
let fileName = "someFileName"
func saveDataToFile(urlStr:String){
let url = NSURL(string: urlStr)
var data:NSData!
let paths = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)
let directory = paths[0]
let filePath = directory.stringByAppendingPathComponent(self.fileName)
print(filePath)//prints /Users/.../Library/Developer/CoreSimulator/Devices/1013B940-6FAB-406B-96FD-1774C670A91E/data/Containers/Data/Application/2F7139D6-C137-48BF-96F6-7579821B17B7/Documents/fileName
let fileManager = NSFileManager.defaultManager()
data = NSData(contentsOfURL: url!)
print(data) // prints a lot of data
if data != nil{
fileManager.createFileAtPath(filePath, contents: data, attributes: nil)
}
}
Now I want to read this data:
func readDataFromFile(){
let paths = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)
let directory = paths[0]
let filePath = directory.stringByAppendingPathComponent(self.fileName)
print(filePath) // prints the same path
let fileManager = NSFileManager.defaultManager()
if fileManager.fileExistsAtPath(filePath){
data = fileManager.contentsAtPath(filePath)
}else{
print("*****BAD*****") // always prints this which means that file wasn`t created
}
}
What`s wrong with the first func? What is the right way to save file to DocumentDirectory?

Answer 1

OK, in this case the answer was following:
First need to create directory (aka folder) and only after that create file inside that directory.
Added to code this:
let fullDirPath = directory.stringByAppendingPathComponent(folderName)
let filePath = fullDirPath.stringByAppendingPathComponent(fileName)
do{
try fileManager.createDirectoryAtPath(fullDirPath, withIntermediateDirectories: false, attributes: nil)
}catch let error as NSError{
print(error.localizedDescription)
}
And as I said after this you create your file:
fileManager.createFileAtPath(filePath, contents: data, attributes: nil)
Thanks to Eric.D
Hope someone will find this useful.