Sep 152016
 

I have only ever used Apache Derby (or Java DB as the version distributed with the JDK is called) in its embedded mode. But then a friend recently told me that he is running it not only in client/server mode but also as a Windows service! This post is about how I recreated that setup with instructions from him.

Let me first list all the tools that I used:

  • JDK 8 (I have update 101 installed) – this includes Java DB
  • Procrun from Apache Commons Daemon
  • NetBeans (optional) as a user friendly way to interact with the database, to make sure that it is up and running

Manually Starting Client/Server Mode

First of all, it is a good idea to enable some kind of authentication. To do this, create a file called derby.properties in the %JDK_HOME%\db\bin folder with these properties (obviously specifying more secure passwords for real world uses):

Now we can start up the server from the command line:

Creating the Database

Read the documentation here for more info about how to create a new database. Keep in mind that if you are using the Java DB installed with the JDK, which by default lives in C:\Program Files, you will need to start up ij from a command prompt with administrator access. If you don’t, it won’t have permissions to create files in the Program Files folder, and you will see an exception when you execute the commit command.

If you are following this step by step, go ahead and create yourself a database now. I called mine firstdb just like in the documentation.

Disconnect and exit from ij before trying to connect from another application such as NetBeans.

Connecting from NetBeans

After exiting ij, I could successfully connect to firstdb from NetBeans:

Connection Properties

Connection Properties

Running as a Service with Procrun

In order to use Procrun, you will need to download the native binaries for Windows. (You can also get there by clicking on the Native binaries link on the Procrun page.)

Create a new folder %JDK_HOME%\db\Windows_Service, and extract prunsrv.exe there. Also create two files (obviously pay attention to paths that may be different on your system):

Install_Service.cmd containing:

Uninstall_Service.cmd containing:

These two files can then be executed to install or uninstall the service. Once the service is installed, start it up in the usual way.

After starting it, the database no longer existed. This is because the working folder was different, and hence the location where the data is read is different. So I just created the new database one last time, by adding the create=true property to the connection in NetBeans.

Aug 092016
 

The Swing-based window system in the NetBeans Platform has the concept of a window that is loaded at runtime. These windows derive from the class TopComponent and are registered using annotations, and are created using a handy wizard in the NetBeans IDE. Today I am going to show you how to do something similar with JavaFX components, using the default lookup of the NetBeans platform. My aim is to load an FXML file and display it on a tabbed pane.

I am using the source code from my previous blog entry as a starting point because I already had it handy. That main fxml file already had a tabPane, which is what I require in the GUI.

Window with basic menu

Application from the previous blog entry

I created a package called za.co.pellissier.javafxwindowsystem.api where the public API of my JavaFXWindowSystem will be located. To be able to add a component to the tabbed pane, the text to be displayed on the tab as well as a javafx.scene.Node object is needed. So I created an interface that windows will need to implement:

package za.co.pellissier.javafxwindowsystem.api;

import javafx.scene.Node;

public interface IJavaFXWindow {

    public Node load();

    String getWindowName();
}

There is a class called FXMLLoader that is able to load an fxml file and return a Node object representing its content. To save future implementers of this API some effort, here is an abstract class that handles the loading:

package za.co.pellissier.javafxwindowsystem.api;

import java.io.IOException;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.fxml.FXMLLoader;
import javafx.scene.Node;

public abstract class AJavaFXWindow implements IJavaFXWindow {
    
    private final String fxmlFileName;

    public AJavaFXWindow(String fxmlName) {
        fxmlFileName = fxmlName;
    }
    
    @Override
    public Node load() {
        try {
            URL resource = getClass().getResource(fxmlFileName);
            return (Node) FXMLLoader.load(resource);
        } catch (IOException ex) {
            Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);
        }
        return null;
    }
}

That is all that there is to the API, for now. :)

Note: Remember to export the package (set it to public) if you want it to be visible to other modules!

So lets look at how it is used by the window system. In my MainWindowController class (the JavaFX controller for the main fxml file), I added this method:

    private void loadWindows() {
        Collection<? extends IJavaFXWindow> windows = 
                Lookup.getDefault().lookupAll(IJavaFXWindow.class);
        for (IJavaFXWindow window : windows) {
            Node win = window.load();
            String name = window.getWindowName();
            tabPane.getTabs().add(new Tab(name, win));
        }
    }

I called this method in the initialize() method after the menu items are loaded.

All that remains is to see how a new window can be added to the system. First, lets create a new module called JavaFXTestWindow to contain the new window. It needs dependencies on Lookup API and JavaFXWindowSystem (the module where the API is defined).

In the JavaFXTestWindow module, I created a new fxml file called testwindow.fxml using SceneBuilder, and generated a controller class using the NetBeans IDE. Now for the most important step… implementing that brand new API!

package za.co.pellissier.testwindow;

import org.openide.util.lookup.ServiceProvider;
import za.co.pellissier.javafxwindowsystem.api.AJavaFXWindow;
import za.co.pellissier.javafxwindowsystem.api.IJavaFXWindow;

@ServiceProvider(service = IJavaFXWindow.class)
public class MyWindow extends AJavaFXWindow implements IJavaFXWindow {

    public MyWindow() {
        super("testwindow.fxml");
    }

    @Override
    public String getWindowName() {
        return "Test Me!";
    }
}

The most important line is the @ServiceProvider annotation – if you leave that out, the default lookup will not be able to find the window!

After cleaning and building, here is the result!

FXML file loaded

FXML file loaded

There are certainly still improvements to be made to this implementation. It only emulates a single mode in the NetBeans Platform Window System. And it requires the user to manually create an additional class. But it is a good start! :)

Jul 262016
 

I was asked some very good questions in response my post about the JavaFX makeover for the NetBeans Platform! Questions with long and interesting answers, questions that sparked more questions in my mind. So here is the first post in response to those questions. :)

Is it possible to reuse normal NetBeans Platform actions?

For the purpose of this exploration, I decided to create a simple NetBeans Platform application to work with. A newly created one, with all of the latest infrastructure available (including annotations for registration). With one action for use today, and one window for another post to follow. So, we start off with this little application:

Simple application to transform

Simple application to transform

The action that I created is registered using annotations:

@ActionID(
        category = "Edit",
        id = "za.co.pellissier.someaction.SomeAction"
)
@ActionRegistration(
        iconBase = "za/co/pellissier/someaction/clickme.png",
        displayName = "#CTL_SomeAction"
)
@ActionReferences({
    @ActionReference(path = "Menu/File", position = 1300),
    @ActionReference(path = "Toolbars/File", position = 200)
})
@Messages("CTL_SomeAction=Action!")
public final class SomeAction implements ActionListener {

At compile time, these annotations are transformed into entries in the generated layer file. And at run time that gets loaded into the System FileSystem. Most days, you would not need to know any of that to work with actions. But today is not most days… :)

If you look at the module project where the action was created in Files view (after cleaning and building the module), you will see the generated-layer.xml file:

Generated layer file

Generated layer file

Looking at the content of the generated layer file, we can see where the action will be registered at runtime:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE filesystem PUBLIC "-//NetBeans//DTD Filesystem 1.2//EN"
                            "http://www.netbeans.org/dtds/filesystem-1_2.dtd">
<filesystem>
    <folder name="Actions">
        <folder name="Edit">
            <file name="za-co-pellissier-someaction-SomeAction.instance">
                <!--za.co.pellissier.someaction.SomeAction-->
                <attr
                    bundlevalue="za.co.pellissier.someaction.Bundle#CTL_SomeAction" name="displayName"/>
                <attr
                    methodvalue="org.openide.awt.Actions.alwaysEnabled" name="instanceCreate"/>
                <attr name="delegate" newvalue="za.co.pellissier.someaction.SomeAction"/>
                <attr name="iconBase" stringvalue="za/co/pellissier/someaction/clickme.png"/>
                <attr boolvalue="false" name="noIconInMenu"/>
            </file>
        </folder>
    </folder>
    <folder name="Menu">
        <folder name="File">
            <file name="za-co-pellissier-someaction-SomeAction.shadow">
                <!--za.co.pellissier.someaction.SomeAction-->
                <attr name="originalFile" stringvalue="Actions/Edit/za-co-pellissier-someaction-SomeAction.instance"/>
                <attr intvalue="1300" name="position"/>
            </file>
        </folder>
    </folder>
    <folder name="Toolbars">
        <folder name="File">
            <file name="za-co-pellissier-someaction-SomeAction.shadow">
                <!--za.co.pellissier.someaction.SomeAction-->
                <attr name="originalFile" stringvalue="Actions/Edit/za-co-pellissier-someaction-SomeAction.instance"/>
                <attr intvalue="200" name="position"/>
            </file>
        </folder>
    </folder>
</filesystem>

An internet search for the system file system reveals this wiki page which gives us the hint that the FileUtil class is going to be a useful one. And finding usages of that class reveals the following interesting method in org.netbeans.core.windows.view.ui.MainWindow:

    private static JMenuBar getCustomMenuBar() {
        try {
            String fileName = Constants.CUSTOM_MENU_BAR_PATH;
            if (fileName == null) {
                return null;
            }
            FileObject fo = FileUtil.getConfigFile(fileName);
            if (fo != null) {
                DataObject dobj = DataObject.find(fo);
                InstanceCookie ic = (InstanceCookie)dobj.getCookie(InstanceCookie.class);
                if (ic != null) {
                    return (JMenuBar)ic.instanceCreate();
                }
            }
        } catch (Exception e) {
            Exceptions.printStackTrace(e);
        }
        return null;
    }

This method is a great and simple example of how to call instanceCreate() for an item registered on the file system. So together with the information from last time, we now have the pieces of information to start implementing the solution. This time I created a file called mainwindow.fxml (remember to update JavaFXWindowManager to load this file):

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>

<AnchorPane prefHeight="371.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="za.co.pellissier.javafxwindowsystem.MainWindowController">
   <children>
      <MenuBar fx:id="menuBar" prefHeight="25.0" prefWidth="600.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
      <TabPane fx:id="tabPane" layoutY="25.0" prefHeight="350.0" prefWidth="600.0" tabClosingPolicy="UNAVAILABLE" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="21.0" />
   </children>
</AnchorPane>

The easiest place to call the code that loads the menu items is in the initialize() method of the controller class. Note that some of the menus, like Window, causes a StackOverflowException when being loaded in this context. It happens because it in turn calls on the Window System that is being loaded. So for now, lets exclude those menus. I also created a layer file and removed some of the File menu actions (see below) for the same reason.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE filesystem PUBLIC "-//NetBeans//DTD Filesystem 1.2//EN" "http://www.netbeans.org/dtds/filesystem-1_2.dtd">
<filesystem>
    <folder name="Menu">
        <folder name="File">
            <file name="Separator3.instance_hidden"/>
            <file name="Separator4.instance_hidden"/>
            <file name="org-netbeans-modules-print-action-PageSetupAction.shadow_hidden"/>
            <file name="org-netbeans-modules-print-action-PrintAction.shadow_hidden"/>
            <file name="org-openide-actions-SaveAction.shadow_hidden"/>
            <file name="org-openide-actions-SaveAllAction.shadow_hidden"/>
            <file name="org-openide-actions-SaveAsAction.shadow_hidden"/>
        </folder>
    </folder>
</filesystem>

So here is the controller class that does the basics of loading the actions and adding them to the JavaFX GUI, after a lot of debugging and hunting for ways to access the user friendly names for the actions.

You will notice several TODOs in the code, and there are probably more things to implement that I haven’t thought of yet. But at least it will point you in the right direction.

public class MainWindowController implements Initializable {

    @FXML
    private MenuBar menuBar;
    @FXML
    private TabPane tabPane;

    /**
     * Initializes the controller class.
     */
    @Override
    public void initialize(URL url, ResourceBundle rb) {
        FileObject systemConfigFile = FileUtil.getSystemConfigFile("Menu");
        FileObject[] menus = systemConfigFile.getChildren();
        for (FileObject menu : menus) {
            // skip the menus that cause a StackOverflowException
            if (menu.getName().equals("Window") || menu.getName().equals("GoTo")
                    || menu.getName().equals("Edit") || menu.getName().equals("View")) {
                continue;
            }
            Menu newMenu = new Menu(menu.getName());
            menuBar.getMenus().add(0, newMenu);
            FileObject[] items = menu.getChildren();
            // TODO Load sub-menus with their own menu items
            for (FileObject item : items) {
                try {
                    DataObject dobj = DataObject.find(item);
                    InstanceCookie ic = (InstanceCookie) dobj.getCookie(InstanceCookie.class);
                    if (ic != null) {
                        Object instance = ic.instanceCreate();
                        if (instance instanceof ActionListener) {
                            ActionedMenuItem menuItem = new ActionedMenuItem((ActionListener)instance);
                            newMenu.getItems().add(menuItem);
                        } else if (instance instanceof JSeparator) {
                            // TODO Add logic to avoid two consecutive separators
                            newMenu.getItems().add(new SeparatorMenuItem());
                        }
                    }
                } catch (IOException | ClassNotFoundException ex) {
                    Exceptions.printStackTrace(ex);
                }
            }
        }
    }
    
    private static class ActionedMenuItem extends MenuItem
    {
        private final ActionListener listener;

        private ActionedMenuItem(ActionListener instance) {
            String displayName = "";
            if (instance instanceof AbstractAction) {
                displayName = ((AbstractAction) instance).getValue("displayName").toString();
            } else if (instance instanceof SystemAction) {
                displayName = ((SystemAction) instance).getName();
            }
            // TODO Deal with & and mnemonics
            setText(displayName);
            
            listener = instance;
            
            setOnAction(new EventHandler<ActionEvent>() {
                @Override
                public void handle(ActionEvent e) {
                    try {
                        SwingUtilities.invokeAndWait(new Runnable() {
                            @Override
                            public void run() {
                                // TODO Create proper action
                                listener.actionPerformed(null);
                            }
                        });
                    } catch (InterruptedException | InvocationTargetException ex) {
                        Exceptions.printStackTrace(ex);
                    }
                }
            });
        }
    }
}
Window with basic menu

Window with basic menubar

Jun 102016
 

I was honoured to present last weekend at the Java 9 and Women in Tech Unconference in Sandton, South Africa. The topic of the presentation was a JavaFX makeover for the NetBeans Platform – get the slides here.

Today I want to share the details of the process of transforming the GUI of an existing NetBeans Platform Application from Swing to JavaFX. There was not enough time to discuss all the details during the presentation, so I prepared the project before I started. However, here I will describe all of the steps that are required. I am using JDK 8, NetBeans 8.1 (the Java SE bundle has everything we need) and Scene Builder 2.0.

1 – Create the sample application

The application that I will be giving a makeover is the Sample CRUD Application that ships with the NetBeans IDE. From the File menu, choose New Project… Browse to the Samples > NetBeans modules category and choose Sample CRUD Application. On the next page of the wizard, specify a location and click Finish.

Creating the Sample CRUD Application

Creating the Sample CRUD Application

At this point, the sample application will not compile – please read my earlier post about Module Dependencies and Java 8 for more information. Here is a brief summary of the two steps that are required:

  • Add a dependency on the Explorer & Property Sheet API for the CustomerEditor module.
  • Remove the Command-line Serviceability module from the application.

Run the application. It should look something like this:

CRUD Application

Running CRUD Application

2 – Create a new module

Lets create a new module to house our JavaFX code. Right-click on the Modules node under the CRUD Customber DB Manager project, and choose Add New… Follow the steps of the wizard – I called my project JavaFXWindowSystem and I chose za.co.pellissier.javafxwindowsystem as my code name base. If you are following step by step, I suggest that you keep at least the code name base the same.

Creating a new module

Creating a new module

3 – Find the right class to replace

It is possible to replace the Window System of the NetBeans Platform because it was designed right from the start in a very modular way. (Reading the platform source code, you might spot cases where there are specialized mock classes in the unit tests that are loaded just like the normal implementations, except during test execution.)

Before continuing, you will have to download and configure the source code of the NetBeans platform if you want to follow the steps. On the NetBeans download page, you will find a link referring to ZIP files for that build. (For the latest version, that link points here.) Download the file ending in platform-src.zip, and extract its contents. In the NetBeans IDE, access Tools > NetBeans Platforms. Under the Sources tab, choose the folder where the extracted source code lives, and close the dialog box.

If you have worked with the NetBeans Window System before, you will probably have encountered the class WindowManager before. This is the most important class when it comes to, well, managing windows. So lets find a spot where we can debug into that class to see what is going on. The easiest spot to put the code is in module CustomerViewer, org.netbeans.modules.customerviewer.CustomerTopComponent, in the method componentOpened(). The framework will call this method when the window is opened. Put these two lines of code into that method:

WindowManager winMngr = WindowManager.getDefault();
winMngr.getMainWindow();

Remember to fix any imports that are missing (Ctrl + Shift + I on Windows).

With the platform source code set up, you can Ctrl + Left Click on the name of the WindowManager class to access the source code of the platform. Go ahead and do so – be brave! :)

public abstract class WindowManager extends Object implements Serializable {

You will notice that WindowManager is in fact an abstract class. So we will need to locate the concrete implementation that needs replacing. The easiest way to do this in a very modular system like this is to debug. So put a breakpoint on the first line that we inserted (by clicking in the left margin) and start the application in debug mode by clicking the Debug Project button on the main toolbar.

When the breakpoint is hit, step over the first line (F8). And then step into the getMainWindow() call on the second line (F7). Take a look at the class that you encounter…

package org.netbeans.core.windows;

...

@org.openide.util.lookup.ServiceProvider(service=org.openide.windows.WindowManager.class)
public final class WindowManagerImpl extends WindowManager implements Workspace {

We have found it – WindowManagerImpl is the class that we need to replace.

4 – Create a basic new WindowManager implementation

In the new za.co.pellissier.javafxwindowsystem package of the new module, create a class called JavaFXWindowManager and add the service provider annotation:

@org.openide.util.lookup.ServiceProvider(service=org.openide.windows.WindowManager.class,
supersedes = "org.netbeans.core.windows.WindowManagerImpl")
public class JavaFXWindowManager extends WindowManager {

The annotation indicates what type of service the class provides, and it also (very important!) indicates that this new implementation will supersede the existing one.

Now we need to add some dependencies in order to resolve all the imports.

Adding a dependency

Adding a dependency

Adding Window System API

Adding Window System API dependency

Add the following dependencies:

  • Lookup API
  • Nodes API
  • Utilities API
  • Window System API

Implement all abstract methods (hint in the margin) and fix imports again if necessary.

Quite a long list of methods will be generated, but thankfully there is only one that we are interested in implementing right now – getMainWindow(). So lets add the basics of creating a window:

@ServiceProvider(service = WindowManager.class, 
                  supersedes = "org.netbeans.core.windows.WindowManagerImpl")
public class JavaFXWindowManager extends WindowManager {

    public static JFrame mMainWindow = new JFrame();

    public JavaFXWindowManager() {

        mMainWindow.setSize(new Dimension(640, 480));
        mMainWindow.addWindowListener(new WindowAdapter()
        {
            @Override
            public void windowClosing(WindowEvent evt)
            {
               LifecycleManager.getDefault().exit();
            }
        }
        );
    }

    @Override
    public Frame getMainWindow() {
        return mMainWindow;
    }

When you fix imports, make sure that you import java.awt.event.WindowEvent and NOT the JavaFX equivalent!

Note that I added a call to the NetBeans Platform’s LifecycleManager when the application is closed. This ensures that the normal process will be followed for shutting the application down, just like the original Window System would have done.

5 – Fix the issues caused by replacing the WindowManager

Clean and build, and then run the application, and have a look at the exception that is raised by the framework:

java.lang.ClassCastException: za.co.pellissier.javafxwindowsystem.JavaFXWindowManager cannot be cast to org.netbeans.core.windows.WindowManagerImpl
    at org.netbeans.core.windows.WindowManagerImpl.getInstance(WindowManagerImpl.java:148)
    at org.netbeans.core.windows.WindowSystemImpl.load(WindowSystemImpl.java:78)
    at org.netbeans.core.GuiRunLevel$InitWinSys.run(GuiRunLevel.java:229)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
...

So we see that there is another class that is involved – WindowSystemImpl. Let us replace it with a new class as well – create a class called JavaFXWindowSystem in the same package:

@ServiceProvider(service=WindowSystem.class, supersedes = "org.netbeans.core.windows.WindowSystemImpl")
public class JavaFXWindowSystem implements WindowSystem {

    @Override
    public void init() {
    }

    @Override
    public void show() {
        JavaFXWindowManager.getDefault().getMainWindow().setVisible(true);
    }

    @Override
    public void hide() {
        JavaFXWindowManager.getDefault().getMainWindow().setVisible(false);
    }

    @Override
    public void load() {
    }

    @Override
    public void save() {
    }
}

This time adding the required dependencies is more difficult. We need a dependency on the Core module – click the Show Non-API Module checkbox to even see it on the list of dependencies.

Add a dependency on Core

Add a dependency on Core

Once it is added, edit the dependency and set it to use implementation version.

Editing dependency

Editing dependency

Setting implementation version

Setting implementation version

If you do not do this, you will see this error message:

The module za.co.pellissier.javafxwindowsystem is not a friend of org-netbeans-core.jar

Do take note that this means that you are setting a dependency on a very specific version of the Core module – should you ever change the version of the NetBeans Platform that you build against, you would have to fix this dependency!

You will have to stop the previous execution from the IDE before running the application again. Running it again now shows a very minimal JFrame:

Empty JFrame

Empty JFrame

6 – Including Branding

A NetBeans Platform Application includes branding information – application icons, splash screen image and so forth. To improve the look of our very basic JFrame, we can use some of these elements:

public JavaFXWindowManager() {

    mMainWindow.setSize(new Dimension(640, 480));
    mMainWindow.addWindowListener(new WindowAdapter()
    {
        @Override
        public void windowClosing(WindowEvent evt)
        {
            LifecycleManager.getDefault().exit();
        }
    }
    );

    String title = NbBundle.getBundle("org.netbeans.core.windows.view.ui.Bundle").getString("CTL_MainWindow_Title_No_Project"); //NOI18N
    if (!title.isEmpty())
    {
        mMainWindow.setTitle(title);
    }
    mMainWindow.setIconImages(Arrays.asList(
        ImageUtilities.loadImage("org/netbeans/core/startup/frame.gif", true),
        ImageUtilities.loadImage("org/netbeans/core/startup/frame32.gif", true),
        ImageUtilities.loadImage("org/netbeans/core/startup/frame48.gif", true)));
    mMainWindow.setLayout(new java.awt.BorderLayout());
}

Add a dependency on the Base Utilities API module and fix imports.

Now the main window title and application icons are set just like would be done for a standard NetBeans Platform application. So you can configure these elements in the normal branding window in the IDE!

With Branding

With Branding

7 – Building a new GUI

All the difficult parts are now done – from this point on, we can develop a normal JavaFX GUI using SceneBuilder and the JavaFX infrastructure in the NetBeans IDE. Here is the contents of my crudwindow.fxml file:

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="276.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="za.co.pellissier.javafxwindowsystem.CrudwindowController">
   <children>
      <ListView fx:id="list" prefHeight="400.0" prefWidth="200.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.topAnchor="0.0" />
      <Label layoutX="220.0" layoutY="18.0" text="Name:" />
      <Label layoutX="220.0" layoutY="52.0" text="City:" />
      <TextField fx:id="txtName" layoutX="269.0" layoutY="14.0" prefHeight="25.0" prefWidth="233.0" />
      <TextField fx:id="txtCity" layoutX="269.0" layoutY="48.0" prefHeight="25.0" prefWidth="233.0" />
   </children>
</AnchorPane>

And the CrudwindowController controller class, which contains bits and pieces copied from the sample code to make the DB access work:

package za.co.pellissier.javafxwindowsystem;

import demo.Customer;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.ResourceBundle;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.ListView;
import javafx.scene.control.TextField;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.Query;
import javax.swing.SwingUtilities;
import org.netbeans.modules.customerdb.JavaDBSupport;

/**
 * FXML Controller class
 *
 * @author Hermien Pellissier
 */
public class CrudwindowController implements Initializable {

    @FXML
    private ListView<CustomerWrapper> list;
    @FXML
    private TextField txtName;
    @FXML
    private TextField txtCity;
    
    private static class CustomerWrapper
    {
        private String displayName;
        private Customer customer;

        public String getDisplayName() {
            return displayName;
        }

        public void setDisplayName(String displayName) {
            this.displayName = displayName;
        }

        public Customer getCustomer() {
            return customer;
        }

        public void setCustomer(Customer customer) {
            this.customer = customer;
        }

        @Override
        public String toString() {
            return displayName;
        }
    }

    /**
     * Initializes the controller class.
     */
    @Override
    public void initialize(URL url, ResourceBundle rb) {
        JavaDBSupport.ensureStartedDB();
        EntityManagerFactory factory = Persistence.createEntityManagerFactory("CustomerDBAccessPU");
        if (factory == null) {
            // XXX: message box?
            return ;
        }
        EntityManager entityManager = null;
        try {
            entityManager = factory.createEntityManager();
        } catch (RuntimeException re) {
            // XXX: message box?
            return ;
        }
        final Query query = entityManager.createQuery("SELECT c FROM Customer c");
        SwingUtilities.invokeLater(new Runnable () {
            @Override
            public void run() {
                @SuppressWarnings("unchecked")
                List<Customer> resultList = query.getResultList();
                List<CustomerWrapper> wrappersList = new ArrayList<>();
                for (Customer customer : resultList) {
                    CustomerWrapper w = new CustomerWrapper();
                    w.setCustomer(customer);
                    w.setDisplayName(customer.getName());
                    wrappersList.add(w);
                }
                ObservableList<CustomerWrapper> items = FXCollections.observableArrayList(wrappersList);
                list.setItems(items);
            }
        });
        
        list.getSelectionModel().selectedItemProperty().addListener(
                new ChangeListener<CustomerWrapper>() {
            @Override
            public void changed(ObservableValue<? extends CustomerWrapper> ov,
                    CustomerWrapper old_val, CustomerWrapper new_val) {
                txtName.setText(new_val.getDisplayName());
                txtCity.setText(new_val.getCustomer().getCity());
            }
        });
    }    
}

Note that you will need a dependency on the CustomerDBAccessLibrary module from the sample app.

The last step is add the code to display the JavaFX scene to the end of the constructor of the JavaFXWindowManager class:

        try {
            JFXPanel fxPanel = new JFXPanel();
            Parent root = FXMLLoader.load(JavaFXWindowManager.class.getResource("crudwindow.fxml"));
            Scene scene = new Scene(root);
            fxPanel.setScene(scene);
            mMainWindow.add(fxPanel, BorderLayout.CENTER);
        }
        catch (IOException ex) {
            Exceptions.printStackTrace(ex);
        }

The complete project structure now looks like this:

Completed Project

Completed Project

And the running application:

The new JavaFX GUI

The new JavaFX GUI

Jun 102016
 

I recently decided to use the Sample CRUD Application that is available in the NetBeans IDE as the basis for a demonstration that I did at a conference. (More about that in a future post.) It is a very useful sample that illustrates how to get up and running with database access from a NetBeans Platform Application.

Side note: The sample is an Ant-based application, which is in my opinion better for a demonstration than a Maven-based one. And that is simply because it won’t want to download dependencies at the worst possible time during the demonstration, making everybody wait. :)

CRUD Application

Running CRUD Application

So I installed JDK 8 and NetBeans 8.1, and without further delay created the application.

Creating the Sample CRUD Application

Creating the Sample CRUD Application

But when I tried to run the application, I got this compile error:

SampleCRUDApp2\CustomerEditor\src\org\netbeans\modules\customereditor\EditorTopComponent.java:362:
error: cannot access ExplorerManager
CustomerTopComponent.refreshNode();
class file for org.openide.explorer.ExplorerManager not found

This appears on the surface to be a really strange error… ExplorerManager is not even mentioned on that line! I decided to just add a dependency on the Explorer & Property Sheet API for the CustomerEditor module, and the code compiled. Now I could use the sample for my demonstration, and I didn’t give it any more thought. But when I sat down this morning to write about the demonstration, I realised that I need to find an explanation for this issue.

Project Structure

Project structure after creation by the wizard

So let us consider the structure of the sample project, as it stands just after creation by the project wizard. It is a very modular design, since that is partially what the sample is meant to demonstrate. The CustomerEditor (the module that is causing the compile error) depends on the CustomerViewer, which is perfectly sensible. And the CustomerViewer does have a dependency on the Explorer & Property Sheet API module from the NetBeans Platform since it uses classes that live there. Again, a perfectly sensible arrangement.

And then it hit me – I have seen this issue before in my own code! When compiling a NetBeans Platform Application on JDK 8, it is sometimes necessary to include direct dependencies on modules that are used by classes in dependent modules. Dependencies that are definitely NOT required when compiling with JDK 7. The sample is not broken, it is simply JDK 8 that is stricter in its requirements when compiling the code!

Side note: Looking at the code in the sample application, we can form an idea of how old the code is. This still has the Settings.xml and Wstcref.xml files for each TopComponent, which means that it dates back to before the introduction of annotations to register TopComponents. :)

One last issue did arise when I ran the application:

Warning - could not install some modules:
Command-line Serviceability - The module named
org.netbeans.modules.autoupdate.services was needed and not found.

This must be due to new modules introduced since the creation of the sample source code. In an Ant-based NetBeans Platform Application, new modules that are introduced in clusters or projects that the application depends on will automatically get included. This is because the way the dependencies are specified is by listing the EXCLUDED modules from each cluster.

I could safely click Disable and Continue without affecting functionality, so I removed the Command-line Serviceability module from the application (CRUD Customer DB Manager project properties > libraries tab) and thus permanently resolved the last issue.

Removing Command-line Serviceability

Removing Command-line Serviceability

Now we are finally ready for the demonstration code… coming soon!

Aug 012014
 

Beans binding makes life so much easier when designing GUIs with the NetBeans IDE. It is well integrated into the GUI builder, and usually it just works out of the box.

Last week I developed a new options panel for a NetBeans Platform Application. Creating the framework for the new panel took maybe a minute using the file wizard that sets up everything for you to link the panel to the Options infrastructure of the Platform. I added a text field or two, and bound their text properties to a bean that I had created for this purpose. When I ran the application, I saw that the binding didn’t do anything at all!

So I dived into the source code of the beansbinding library. I debugged through lots and lots of source code – first in a plain old Java application where the binding did work as expected, and then in the platform application that was giving me trouble. I spent maybe an hour and a half deep down in the depths of that library. And then suddenly I found the source of my problem! If you look carefully at the source code in the NetBeans Options Window Module Tutorial, and knew what you were looking for, this like would jump out at you:

The cause of my trouble is that this panel class is NOT public! In retrospect, this makes a lot of sense. Beans binding does a lot of operations via reflection, and if the class is not public the library won’t have access to it!

Tip of the month
For beans binding to work with any GUI panel, that panel must be public!
Nov 302013
 

The NetBeans IDE has some great refactoring tools. It makes lots of tasks so much less error prone than doing them manually. In this article, I describe some of my favourite refactoring tools. (These tools can be accessed from the main menu bar (Refactor) or from the context menu of a Java file open in the editor.)

#1 – Rename

Anything that has a name can be renamed. But my favourite example is renaming a class.

refactor01

 

When a class is renamed, not only the source code of the class (optionally including comments) is changed, but also the name of the file where it lives. And also any usages of the class elsewhere in your open projects!

#2 – Encapsulate Fields

This feature allows you to generate getters, setters and property change support for fields in a class. It allows you to specify various parameters, such as the visibility of the accessors. So lets take a very simple class, and apply the Encapsulate Fields tool:

refactor02

 

… and lets look at the generated code:

refactor03

 #3 – Extract Interface

If you have an existing class, and you want to extract some of its methods into an interface, the NetBeans IDE has just the tool for you!

refactor04

 

Not only does the interface get generated, but your class is automatically changed to implement the new interface too!

refactor05

#4 – Introduce Method

Sometimes one wants to extract some lines of code into a separate method. Maybe because the initial method is becoming too long to be readable, or because that part of the functionality will be reused elsewhere. Whatever the motivation, the NetBeans IDE has just the tool for the job! So lets look at a silly example where an identical piece of code occurs twice in the same class:

refactor06

And then lets look at the result of the refactoring:

refactor07

Tip: Experiment with extracting large, complicated blocks of code – the NetBeans IDE is capable of much more than this simple example!

#5 – Change Method Parameters

Say we decide to now introduce a new parameter for the extractedMethod() created above. If we did this manually, it would mean changing each place where the method is called manually too. (Sometimes this is desirable, but it can be a lot of effort.) With the Change Method Parameters feature, this task becomes much easier, since it allows you to specify a default value for the new parameter.

refactor08

Now our class looks like this:

refactor09

Tip: Also try out the Create New Method and Delegate from Existing Method option!

Nov 152013
 

The NetBeans IDE has so many wonderful features that makes a Java developer’s life easier. And many of these features have keyboard shortcuts attached to them. So I decided to make a list of the shortcuts that I think every developer should know.

  • Ctrl+O : Quickly go to a class
    This shows a dialog that allows you to start typing the name of the class that you are looking for. You can then choose the class from a list of matched names.
  • Ctrl+Shift+I : Fix imports
    Add any new imports that are necessary and remove unused ones at the same time. If a class name matches multiple possibilities, a dialog is displayed that allows you to choose which class to import.
  • Alt+Shift+F : Format selection
    Format the selected code according to the rules that can be changed in the IDE Options > Editor > Formatting. This is also a handy way to format XML in a useful way.
  • Alt+F7 : Find usages
    Find where the currently selected type is used.
  • Ctrl+R : Rename
    Rename the selected variable or class, refactoring if required.
  • Alt+Insert : Generate code
    Choose from various context sensitive items that the IDE can generate, for example generating getters and setters.
  • Ctrl+Space : Auto complete
    Context sensitive auto complete.
  • Ctrl+/ : Toggle comment lines
    Adds // to the start of each of the selected lines. Or removes these if present.
  • Ctrl+Shift+Up/Down : Copy lines up/down
    Make a copy of the currently selected lines, without going through the clipboard.
  • Alt+Shift+Up/Down : Move lines up/down
    Move the currently selected lines, without going through the clipboard.

For a much more comprehensive list of keyboard shortcuts, have a look at Highlights of NetBeans IDE 7.4 Keyboard Shortcuts & Code Templates.

Sep 022013
 

Creating a wizard in a NetBeans Platform Application is quite easy since there is a NetBeans IDE new file wizard that creates all of the scaffolding for you. Have a look at the NetBeans Wizard Module Tutorial for a step by step description of how to work with the normal, modal wizards.

In the above tutorial, the DemoWizardAction class contains the sample code for calling the wizard. The relevant code for displaying the modal wizard is duplicated below for easy reference:

WizardDescriptor wiz = new WizardDescriptor(
        new WizardDescriptor.ArrayIterator<WizardDescriptor>(panels));
if (DialogDisplayer.getDefault().notify(wiz) == WizardDescriptor.FINISH_OPTION) {
    // do something
}

I recently ran into a use case where it was required that the wizard must be non-modal. Whether this is a desirable behaviour for a wizard is a topic all of its own, so lets just assume that we want to be able to do this. The code to display the wizard as non-modal is shown below:

WizardDescriptor wiz = new WizardDescriptor(
        new WizardDescriptor.ArrayIterator<WizardDescriptor>(panels));
Dialog wizardDialog = DialogDisplayer.getDefault().createDialog(wiz);
wizardDialog.setModal(false);
wizardDialog.setVisible(true);

Now the remaining complication is being able to catch the event that indicates that the wizard completed with the option WizardDescriptor.FINISH_OPTION as in the original code. I noticed that the WizardDescriptor allows for the registration of property change listeners. And so by debugging into the propertyChange method, I was able to determine what must be handled to catch this particular event:

WizardDescriptor wiz = new WizardDescriptor(
        new WizardDescriptor.ArrayIterator<WizardDescriptor>(panels));
wiz.addPropertyChangeListener(new PropertyChangeListener() {

    @Override
    public void propertyChange(PropertyChangeEvent evt) {
        if (evt.getNewValue() != null && "org.openide.WizardDescriptor.FinishAction".
                 equals(evt.getNewValue().getClass().getCanonicalName())) {
            // do something
        }
    }
});

Dialog wizardDialog = DialogDisplayer.getDefault().createDialog(wiz);
wizardDialog.setModal(false);
wizardDialog.setVisible(true);