使用 toString 拆分 observableList

Question

So I am trying to split an observableList using toString:

listeMedLag = DataHandler.hentDataCupLag("src/arrangementer.csv",2,listeMedLag,cup); //output: Skjeberg&Borgen
listeMedLag.toString().split("&");
lagSomErMed.setItems(listeMedLag); //output: Skjeberg&Borgen

Anybody know why the list ain't splitting?

Answer 1

listeMedLag.toString()

Creates a string based on the elements of the list. There are multiple problems with that. The ObservableList implementation may not create exactly the string output you expect. Also usually there are {} wrapping the content.

Also invoking methods on objects returned by methods of an object usually won't have an effect on the original object. There are exceptions, but they are documented. (Examples would be List.subList and List.iterator ). String is immutable though and it has no connection to the list whatsoever. Calling split on the string simply results in an new String[] array being created that contains parts of the string. It has no effect on the string object and also no effect on the list.

If your intention is to split every element of a List<String> and fill a list with all those elements I recommend you create a new list containg all those elements and then assign the contents to the target list:

List<String> inputList = ...
ObservableList<String> outputList = FXCollections.observableArrayList();

// fill new list with elements of original list split at "&"
inputList.stream().map(s -> s.split("&")).forEach(outputList::addAll);

// do something with new list
listView.setItems(outputList);

Answer 2

You need to store that splitted string into a local variable. like:

String[] split =  = listeMedLag.toString().split("&");
lagSomErMed.setItems(split);

or

lagSomErMed.setItems(listeMedLag.toString().split("&"));

split method signature:

public String[] split(String regex)