Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8095299

[TableView] TableView with null items throws NPE on sorting

    XMLWordPrintable

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 8u5
    • Fix Version/s: 8u60
    • Component/s: javafx
    • Labels:

      Description

      Basically, table sorting doesn't seem able to handle a null value of the table's items property. Couldn't find any documentation about whether or not a null value is allowed, so the bug is either

      - null allowed: implementation error in default sort policy, which hands over the items as returned from getItems without checking if it is null
      - null not allowed: should be specified in setItems/constructor and fail-fast with an NPE

      Seeing the implemenation at other places (like: " // we quite happily accept items to be null here" in the constructor and all/most? other collaborators checking against null), I assume the first (and personally, I am quite happy if that indeed were the intention). There are good arguments either way, though, just should be clearly specified.

      To reproduce:

      - run the example below
      - click on header

      expected: do nothing (except changing the header icon)

      actual: throws NPE

      Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
      at java.util.ArrayList.<init>(ArrayList.java:168)
      at javafx.collections.FXCollections.sort(FXCollections.java:672)
      at javafx.scene.control.TableView$3.call(TableView.java:467)
      at javafx.scene.control.TableView$3.call(TableView.java:431)
      at javafx.scene.control.TableView.sort(TableView.java:1430)
      at javafx.scene.control.TableView.doSort(TableView.java:1460)
      at javafx.scene.control.TableView.access$100(TableView.java:354)
      at javafx.scene.control.TableView$4.onChanged(TableView.java:532)


      Runnable example:

      /**
       * Issue TableView throws NPE on sorting column if items property value is null.
       *
       * @author Jeanette Winzenburg, Berlin
       */
      public class TableSortNPEIfNullItems extends Application {

          private Parent getContent() {
              // instantiate the table with null items
              TableView<String> view = new TableView<String>(null);
              TableColumn<String, String> column = new TableColumn<>("Items");
              // either click on header for sorting
              view.getColumns().addAll(column);
              // or add column to sort order immediately
              //view.getSortOrder().add(column);
              Pane parent = new HBox(100);
              parent.getChildren().addAll(view);
              parent.setPadding(new Insets(20));
              return parent;
          }
          
          @Override
          public void start(Stage primaryStage) throws Exception {
              Scene scene = new Scene(getContent());
              primaryStage.setTitle(System.getProperty("java.version"));
              primaryStage.setScene(scene);
              primaryStage.show();
          }

          public static void main(String[] args) {
              launch();
          }
          
      }

        Attachments

          Activity

            People

            Assignee:
            jgiles Jonathan Giles
            Reporter:
            fastegal Jeanette Winzenburg
            Votes:
            0 Vote for this issue
            Watchers:
            5 Start watching this issue

              Dates

              Created:
              Updated:
              Resolved:
              Imported: