Asynchronous load of content within Pagination - asynchronous

Question

I am search an pagination example for loading data asynchron from a server. I have no clue how to solve that with the pagination control of javafx. Well i hava an example where an observable list is loaded in the background with 10k of items. But i only want to load the items for a page when its actually needed. So only when the user switcht to the next page i want to grab the next 20 items with a task. When the task is done the page should be rendered..
Thanks for any advice and help!
Link to observable example:
https://forums.oracle.com/forums/thread.jspa?messageID=10976705#10976705

Answer 1

All you need is to start a background thread with your task once user clicked on a page. See next example which uses sites downloading for a long task:
public class Pages extends Application {
#Override
public void start(Stage primaryStage) {
final Pagination root = new Pagination(urls.length, 0);
root.setPageFactory(new Callback<Integer, Node>() {
// This method will be called every time user clicks on page button
public Node call(final Integer pageIndex) {
final Label content = new Label("Please, wait");
content.setWrapText(true);
StackPane box = new StackPane();
box.getChildren().add(content);
// here we starts long operation in another thread
new Thread() {
String result;
public void run() {
try {
URL url = new URL(urls[pageIndex]);
URLConnection urlConnection = url.openConnection();
urlConnection.setConnectTimeout(1000);
urlConnection.setReadTimeout(1000);
BufferedReader breader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
StringBuilder stringBuilder = new StringBuilder();
String line;
while ((line = breader.readLine()) != null) {
stringBuilder.append(line);
}
result = stringBuilder.toString();
} catch (Exception ex) {
result = "Download failed";
}
// once operation is finished we update UI with results
Platform.runLater(new Runnable() {
#Override
public void run() {
content.setText(result);
}
});
}
}.start();
return box;
}
});
Scene scene = new Scene(root, 300, 250);
primaryStage.setTitle("Pages!");
primaryStage.setScene(scene);
primaryStage.show();
}
private final static String[] urls = {"http://oracle.com", "http://stackoverflow.com", "http://stackexchange~.com", "http://google.com", "http://javafx.com"};
public static void main(String[] args) {
launch(args);
}
}