How can I Call method from another class using JavaFX

Question

We have two windows :

the first one represent a tableview which containts some database data , and 3 buttons ( Add , Delete , Refresh )

The second window is called when clicking the add button : here we have some textfields to save data into the database .

Now the problem is that I want to refresh the tableview ( in the first window ) just after I click a Submit button from the second window so I can see these changes in the table , I have tried to create an object from the first class and then call the refresh method but it gives me java.lang.NullPointerException.

Here is the first controller which contains the tableview

public class DeptControl implements Initializable {

 @Override
public void initialize(URL url, ResourceBundle rb) {
    deptid.setCellValueFactory(new PropertyValueFactory<>("DeptNo"));
    deptid.setEditable(false);
    deptname.setCellValueFactory(new PropertyValueFactory<>("DeptName"));
    deptname.setCellFactory(TextFieldTableCell.forTableColumn());
    deptlocation.setCellValueFactory(new PropertyValueFactory<>("Location"));
    deptlocation.setCellFactory(TextFieldTableCell.forTableColumn());
    table.setTableMenuButtonVisible(true);

    filltable(); // THIS IS THE REFRESH METHODE
}

int id;
String DEPTNAME;
String DEPTLOCATION;

public void set(){
     id  =table.getSelectionModel().getSelectedItem().getDeptNo();
     DEPTNAME = table.getSelectionModel().getSelectedItem().getDeptName();
     DEPTLOCATION = table.getSelectionModel().getSelectedItem().getLocation();
}  
public  void filltable(){
    Department dep = new Department();
    dep.GetAllRows(table);
}

Now the second controller java (the add window)

public class DeptAddControl  implements Initializable{

@Override
public void initialize(URL location, ResourceBundle resources) {
    clear();
}

private void clear(){
    txtDeptID.setText(new Department().AutoNumber());
    txtDeptName.clear();
    txtLocation.clear();
    txtDeptName.requestFocus();
}


@FXML
private void submit(ActionEvent event) {
        int num = (Integer.parseInt(txtDeptID.getText()));
        String name = (txtDeptName.getText());
        String location = (txtLocation.getText());
        Department e = new Department(num,name,location);
        btnback.fire();
        e.add();
        /// Now the data is added and I want to call filltable() from the other class 
        DeptControl dp = new DeptControl();
        dp.filltable();  //I tried this but gives Exception
    }

@FXML
private void back(ActionEvent event) {
    Stage stage = (Stage)btnback.getScene().getWindow();
    stage.close();
    }

}

Exception

Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
    at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Node.fireEvent(Node.java:8413)
    at javafx.scene.control.Button.fire(Button.java:185)
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
    at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:380)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:294)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:416)
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:415)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
    at com.sun.glass.ui.View.notifyMouse(View.java:937)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
    ... 52 more
Caused by: java.lang.NullPointerException
    at Entity.Department.GetAllRows(Department.java:125)
    at controllers.DeptControl.filltable(DeptControl.java:119)
    at controllers.DeptAddControl.submit(DeptAddControl.java:68)
    ... 62 more

The GetAllRows() which throws the exception

@Override
    public void GetAllRows(TableView table) {
        ObservableList<Department> list = FXCollections.observableArrayList();
        ResultSet rs = go.FillTable("department_data");
        try{
        while (rs.next()){
                list.add(new Department( rs.getInt(1) , rs.getString(2), rs.getString(3)));
            }
            con.close();
            table.setItems(list);

        }catch(SQLException e){
            tools.Notification_Error("Error", e.getMessage(), Pos.CENTER);
        }
    }

Here is the Filltable()

public static ResultSet FillTable(String TableNameOrStatement) {
        try {
            connect();
            Statement s = con.createStatement();
            String Query;          
            if("select ".equals(TableNameOrStatement.substring(0, 7).toLowerCase())){
                Query = TableNameOrStatement;
            }             
            else {
                Query = "select * from " + TableNameOrStatement;
            }
            ResultSet rs = s.executeQuery(Query);
            return rs;
        } catch (SQLException ex) {
            tools.Notification_Error("Error", ex.getMessage(), Pos.CENTER);  
            return null;
        }
    }

please post the full stracktrace. the exception must be thrown within the `filltable()` method — Neuron, Nov 04 '17 at 11:53
the exception gets thrown somewhere within the method `GetAllRows()` which you haven't posted — Neuron, Nov 04 '17 at 12:29
is there any specific method to communicate between controllers?? — Chawkii, Nov 04 '17 at 12:53
Added a bunch of questions that essentially ask the same thing. You need access to the actual controller; your `@FXML`-injected fields are only initialized in the controller. They are not initialized in the `dp` object you create in `submit()`. — James_D, Nov 04 '17 at 15:20

score -1 · Answer 1 · answered Nov 04 '17 at 00:59

-1

DeptControl.filltable();

Could be other issues, though.

answered Nov 04 '17 at 00:59

JeffBship

527
1
4
11

the methode is not static so I can't do that – Chawkii Nov 04 '17 at 11:49

How can I Call method from another class using JavaFX

1 Answers1