There is a following method:

public static list & lt; string & gt; GetMessageOfbindingResult (BindingResult Result) {
  RETURN RESULT.GETFIELDERRORS (). Stream ()
      .map (Fe - & gt; string.format ("[% s]% s", Fe.GetField (), Fe.GetDefaultMessage ()))
      .collect (collectors.tolist ());
}

There is a need to return an array of String [] instead of the list LIST & LT; String & GT; . In Stream API there is a toarray () terminal operation, but it returns an Object array. So far I did like this:

Public Stating String [] GetMessagesOFBindingResult (BindingResult Result) {
    List & LT; Fielderror & GT; errors = result.getfielderrors ();
    String [] Messages = New String [Errors.size ()];
    For (int i = 0; i & lt; errors.size (); i ++) {
      Messages [i] = String.Format ("[% s]% s", errors.get (i) .getfield (), errors.get (i) .getDefaultMessage ());
    }
    Return Messages;
  }

But it seems to me that the desired array can be obtained easier, without creating a heap of intermediate lists.

Is there any opportunity to get the array string [] with Stream API?

Answer 1, Authority 100%

If Stream API will offer so

Public Static Void Main (String [] Args) {
  List & lt; String & GT; List = New ArrayList & LT; & GT; ();
  List.ADD ("String1");
  List.add ("String2");
  List.add ("String3");
  List.Add ("String4");
  String [] Result = List.Stream (). Collectors.Tolist ()). Toarray (New String [0]);
  For (String String: Result) {
   System.Out.printLN (String);
  }
 }

And if not, so

Public Static Void Main (String [] Args) {
  List & lt; String & GT; List = New ArrayList & LT; & GT; ();
  List.ADD ("String1");
  List.add ("String2");
  List.add ("String3");
  List.Add ("String4");
  String [] Result = List.ToArray (New String [0]);
  For (String String: Result) {
   System.Out.printLN (String);
  }
 }

the idea of ​​both one and the same use TOARRAY

In your case it will be so

Public Static String [] GetMessageOfBindingResult (BindingResult Result) {
  RETURN RESULT.GETFIELDERRORS (). Stream ()
      .map (Fe - & gt; string.format ("[% s]% s", Fe.GetField (), Fe.GetDefaultMessage ()))
      .collect (Collectors.Tolist ()). Toarray (New String [0]);
}

Answer 2, Authority 33%

You can do, for example, so:

string [] strings = intstream
  .range (5, 100)
  .Boxed ()
  .map (String :: Valueof)
  .toarray (String [] :: New);

Make I took Stream from Integer just as an example. Next, we transform everything into the string and last line we say that we need an array.