Check out example codes for "filesaver javafx". It will help you in understanding the concepts better.

Code Example 1

FileChooser fileChooser = new FileChooser();
 
//Set extension filter for text files
FileChooser.ExtensionFilter extFilter = new FileChooser.ExtensionFilter("TXT files (*.txt)", "*.txt");
fileChooser.getExtensionFilters().add(extFilter);

//Show save file dialog
File file = fileChooser.showSaveDialog(primaryStage);
//Its important towrite showSaveDialog!!!

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