How to fill the treeTableView correctly

Question

I have a record in database which being get must be in the tree table view. Here is the filling method:

 private void updateGoods(){
        goodsPane.setCenter(goodTreeTableView);
        List<Good> goodAndFoldersList;
       try {
           goodAndFoldersList = goodsService.getGoods();//database query
       }catch (SQLException e){
           goodAndFoldersList = new ArrayList<>();
           log.log(Level.ERROR, e.getMessage());
       }
           List<Good> goods = new ArrayList<Good>();//list for roots
           List<Good> roots = new ArrayList<Good>();//list for goods themselves
           for (Good good : goodAndFoldersList) {
               if (good.isIs_folder()) {
                   roots.add(good);
               } else {
                   goods.add(good);
               }
           }
           TreeItem<Good> rootItem = new TreeItem<>();//the main root
           for (Good root : roots) {
               Long folderId = root.getId();
               TreeItem<Good> rootTreeItem = new TreeItem<>(root);
               for (Good good : goods) {//looking for goods for each folder
                   if (good.getFolderId() == folderId) {
                       TreeItem<Good> goodTreeItem = new TreeItem<>(good);
                       rootTreeItem.getChildren().add(goodTreeItem);
                   }
               }
               rootItem.getChildren().add(rootTreeItem);//adding every folder to the main root
           }        
           goodTreeTableView = new TreeTableView<>(rootItem);
    }

after this method user doesn't see anything in the treeTableView. Maybe there nessessary to define cell content, but this code being put before goodTreeTableView = new TreeTableView<>(rootItem); drops NullPointerException:

        goodName.setCellValueFactory((TreeTableColumn.CellDataFeatures<Good, String> param) ->
                new ReadOnlyStringWrapper(param.getValue().getValue().getName()));
        folderId.setCellValueFactory((TreeTableColumn.CellDataFeatures<Good, Number> param) ->
                new ReadOnlyLongWrapper(param.getValue().getValue().getFolderId()));
        is_folder.setCellValueFactory((TreeTableColumn.CellDataFeatures<Good, Boolean> param) ->
                new ReadOnlyBooleanWrapper(param.getValue().getValue().isIs_folder()));

I guess this is the reason of my problem but why this drops NPE I can't figure out.

UPD: if I add setting cell value factory I get the following stacktrace:

javafx.fxml.LoadException: 
/D:/javaEdi/linkserver/ediagent/target/classes/com/ediagent/edi/gui/Main.fxml

    at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2595)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2565)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2435)
    at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2403)
    at com.ediagent.edi.gui.Main.initRootLayout(Main.java:44)
    at com.ediagent.edi.gui.Main.start(Main.java:27)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$153(LauncherImpl.java:821)
    at com.sun.javafx.application.LauncherImpl$$Lambda$51/1546859350.run(Unknown Source)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$166(PlatformImpl.java:323)
    at com.sun.javafx.application.PlatformImpl$$Lambda$44/1712669532.run(Unknown Source)
    at com.sun.javafx.application.PlatformImpl.lambda$null$164(PlatformImpl.java:292)
    at com.sun.javafx.application.PlatformImpl$$Lambda$47/157858792.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$165(PlatformImpl.java:291)
    at com.sun.javafx.application.PlatformImpl$$Lambda$46/1225373914.run(Unknown Source)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$141(WinApplication.java:102)
    at com.sun.glass.ui.win.WinApplication$$Lambda$37/152005629.run(Unknown Source)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2560)
    ... 18 more
Caused by: java.lang.NullPointerException
    at com.ediagent.edi.gui.MainController.updateGoods(MainController.java:309)
    at com.ediagent.edi.gui.MainController.initialize(MainController.java:328)
    ... 28 more

**UPD:**rootItem:

have you checked if roottreeitem is actually getting any variables? — Jeremy C., May 12 '15 at 07:17
try goodTreeTableView.setRoot(rootItem) instead of new Treetableview — Jeremy C., May 12 '15 at 07:21
@JeremyC. of cource roottreeitem has value. As for se using setRoot(rootItem) instead of new TreeTableView I get the nullPointerException — Nikitin Mikhail, May 12 '15 at 07:25
@ItachiUchiha No I don't spread it to threads as there are no need — Nikitin Mikhail, May 12 '15 at 07:26
that means your rootItem is either null or your goodTreeTableView, have you run through your code with debug? to see the value of your rootItem before you try to use it to set up your treetableview? — Jeremy C., May 12 '15 at 07:26
@NikitinMikhail If the `goodTreeTableView` is a part of FXML, you should not re-initialize it. But it is not the reason for NPE. Please add code for `MainController`. — ItachiUchiha, May 12 '15 at 07:37
@ItachiUchiha you are right. goodtreetableview was null as far as it was'n initialized but only declared. I did the following: goodTreeTableView = new TreeTableView<>(); goodTreeTableView.setRoot(rootItem); — Nikitin Mikhail, May 12 '15 at 07:39
but still see an empty list in gui. I'll add an image in a minute — Nikitin Mikhail, May 12 '15 at 07:40
@ItachiUchiha it is a part of FXML. the MainController code is in the beginning of the question. method updateGoods. it is invoked on tabSelectionChanged — Nikitin Mikhail, May 12 '15 at 07:43

score 1 · Accepted Answer · answered May 12 '15 at 07:48

1

You are adding the data to an GUI element on FXML, by re-initializing it. Avoid re-initialization of FXML elements.

You can change the signature of updateGoods() to :

public TreeItem<Good> updateGoods() {
...
}

and use it in the MainController to set items

goodTreeTableView.setRoot(updateGoods());

Preferably, you can also return only data(List) from updateGoods() instead of returning a TreeItem. Create it in the Controller and set it as the root of goodTreeTableView.

answered May 12 '15 at 07:48

ItachiUchiha

36,135
10
122
176

1

If it is a part of fxml, why is it null. Aren't you annotating it with @FXML? – ItachiUchiha May 12 '15 at 08:06
oh, yes - that was the nullPointerException reason. But in the GUI I still see only empty strings. May it be because of cell value factory is not set for TreeTableColumns? – Nikitin Mikhail May 12 '15 at 08:14
I can't set cell value factory as far as treeTableColumns a null, but they are the part of FXML and annotated with @FXML – Nikitin Mikhail May 12 '15 at 08:28
I cannot comment unless I see what you are trying to do. Please ask a separate question with specify data. – ItachiUchiha May 12 '15 at 08:35

How to fill the treeTableView correctly

1 Answers1