Java ME MIDP Development Quick Start
Guide
This tutorial guides
you through the basic steps of using NetBeans IDE to create a Java™ Platform,
Micro Edition (Java™ ME platform), Mobile Information Device Profile (MIDP)
application and is designed to get you started with mobile application
development as quickly as possible. The tutorial takes you through some of the
basic steps of working with the project system. We show you two ways to create
a Java ME MIDP project named "MyHello" that displays the text
"Make My Day" in a device emulator. This tutorial prepares you to use
other IDE features for developing CLDC/MIDP applications.
Contents
To complete this
tutorial, you need the following software and resources:
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Software or Resource
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Version Required
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Version 7.4
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Version 7
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Depends on the operating system
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Important: The table below lists versions of Oracle
Java ME SDK required for particular platforms.
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Platform
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SDK Version Required
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Microsoft Windows
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Mac OS X
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Linux
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Setting Up the IDE with Oracle Java ME SDK
(Windows only)
Important: This section applies to Windows
platforms only.
To set up NetBeans IDE
with the Oracle Java ME SDK for the Windows platform, you need to:
- install Oracle Java ME SDK
- activate the Java ME feature in NetBeans
IDE
- install the Oracle Java ME Platform SDK
in NetBeans IDE
To install Oracle Java
ME SDK:
- Go to the Java ME SDK
download page.
- Click the Accept License Agreement
option.
- Download the oracle-jmesdk-3-4-rr-win32-bin.exe installer file and save it to any
location on your computer.
- Double-click the installer file to run
the installer, and follow the instructions.
When the installation is complete, the Java (TM) ME Platform SDK 3.4
Device Manager icon ( 
)
appears in the Windows system tray.
To activate the Java
ME feature:
- Choose Tools > Plugins from the main
IDE's toolbar.
- In the Plugins dialog box, click the
Installed tab and select Java ME in the list of available features.
- Click Activate.
- At the Welcome panel of the Installer
dialog box, click Activate.
- When the activation is successfully
completed, click Finish.
- Click Close to close the Plugins dialog
box.
To install the Oracle
Java ME Platform:
- Choose Tools > Java Platforms.
The Java Platform Manager dialog box displays.
- Click Add Platform.
- In the Select Platform Type of the Add
Java Platform wizard, select Java ME CLDC Platform Emulator and click
Next.
The IDE displays the Choose directory to search for platforms dialog box.
- Select the directory you installed the
Java ME SDK Platform to (for example, C:\Java_ME_Platform_SDK_3.4) and click Open.
- In the Platform Folders panel of the Add
Java Platform wizard, ensure the platform you selected in the previous
step is chosen and click Next.
- As soon as the IDE detects the platform,
click Finish in the Detected Platforms panel of the the Add Java Platform
wizard.
The
Oracle Java ME Platform is now registered in the Netbeans IDE.
- In the Java Platform Manager dialog box,
click Close.
Now your NetBeans IDE
is set up for mobile development.
Creating a MIDP Application Using the Source
Editor
Using the Source Code
Editor, you manually create the code for your MIDlets. Creating code in the
Source Code Editor gives you more flexibility when editing the code, and
enables you to insert preprocessor code blocks. You are going to create a MyHello application using the New Project and
New File wizards, and complete the code using the Source Editor.
Creating a New Java ME MIDP Project
- Choose File > New Project. Under Categories, select Java ME. Under Projects, select Mobile Application and click Next.
- Enter MyHelloMIDlet in the Project Name field (note that MID is in upper case letters). Specify
the Project Location. We refer to this directory as $PROJECTHOME in this tutorial.
- Deselect the Create Default Package and
Main Executable Class checkbox and click Next.
- Select the default emulator platform and
use the remaining defaults. Click Finish.
The IDE creates the $PROJECTHOME/MyHelloMIDlet project folder. The project folder contains all of
your sources and project metadata, such as the project Ant script.
- Right-click the MyHelloMIDlet node in the Projects window and
choose New > MIDlet.
- Enter HelloMIDlet as the MIDlet name (note that "MID" is not
in upper case letters by default). Click Finish.
The HelloMIDlet.java file is created.
- Double-click the HelloMIDlet.java file to display the source code in
the IDE's Editor window.
- Click in the Source Editor and
change public class HelloMIDlet extends MIDlet to
9. public class HelloMIDlet
10.extends
MIDlet implements javax.microedition.lcdui.CommandListener
{
- Add the following text before the startApp() method:
12. private
void initialize() {
13. javax.microedition.lcdui.Display.getDisplay(this).setCurrent(get_helloTextBox());
14. }
15.
16. public
void commandAction(javax.microedition.lcdui.Command command,
javax.microedition.lcdui.Displayable displayable) {
17. if
(displayable == helloTextBox) {
18. if
(command == exitCommand) {
19. javax.microedition.lcdui.Display.getDisplay(this).setCurrent(null);
20. destroyApp(true);
21. notifyDestroyed();
22. }
23. }
24. }
25.
26. private
javax.microedition.lcdui.TextBox get_helloTextBox() {
27. if
(helloTextBox == null) {
28. helloTextBox
= new javax.microedition.lcdui.TextBox(null, "Hello Test Code", 120,
0x0);
29. helloTextBox.addCommand(get_exitCommand());
30. helloTextBox.setCommandListener(this);
31. }
32. return
helloTextBox;
33. }
34.
35. private
javax.microedition.lcdui.Command get_exitCommand() {
36. if
(exitCommand == null) {
37. exitCommand
= new javax.microedition.lcdui.Command("Exit",
javax.microedition.lcdui.Command.EXIT,
38. 1);
39. }
40. return
exitCommand;
41. }
42. javax.microedition.lcdui.TextBox
helloTextBox;
javax.microedition.lcdui.Command exitCommand;
- Add a line initialize(); to the startApp() method, so it looks like the
following:
44. public
void startApp() {
45.initialize();
}
Editing the Java Source Code
Now let's add some text
for our MIDlet to display.
In the get_helloTextBox() method, replace the example Hello Test Code code with the text of your choice (for
example,Make
My Day.).
Compiling and Running the Project
Choose Run > Run Project (MyHelloMIDlet) from the main IDE's toolbar. Follow the
progress of the project compilation in the Output window. Note that the HelloMIDlet.java file is built before it is executed. A device
emulator opens to display the results of the executed MIDlet and displays the
text you entered in the source code.
To close the MIDlet
and the emulator window, choose Application > Exit in the emulator window.
Creating a MIDP Application Using the Visual Mobile Designer
The NetBeans IDE
provides a wizard that enables you to quickly create a MIDP project. When
creating the project, you can choose to develop your application in the Visual
Mobile Designer (VMD) or in the Source Code Editor. Using the VMD gives you the
ability to visually plan out the flow of the application and design the screens
the application uses. The designer automatically creates the code for the
application as changes are saved on the design canvas.
Important: To run the Visual Mobile Designer in the
IDE you need to install the Visual Mobile Designer plugin from the Update
Center as follows:
- Choose Tools > Plugins from the main
menu.
- On the Available Plugins tab of the
Plugins dialog box, select Visual Mobile Designer and click Install.
- At the Welcome page of the Installer
dialog box, click Next.
- At the License Agreement page, read the
license agreements associated with the plugin. If you agree to the terms
of all of the license agreements, click the appropriate option and then
click Install.
- (Optional) Select the Run in the
Background option to run the installation in the background.
- When the installation process is
complete, click Finish.
- In the Plugins dialog box, click Close.
Creating a MIDP/CLDC Application
- Choose File > New Project
(Ctrl+Shift+N). Under
Categories, select Java ME. Under Projects,
select Mobile Application and click Next.
- Enter MyHello in the Project Name field. Use the default Project
Location, or change it to the directory you prefer on your system. In this
tutorial we refer to this directory as $PROJECTHOME.
- Leave the Create Default
Package and Main Executable Class check box selected. Click Next.
- Select the default as the emulator
platform and use the remaining defaults. Click Finish.
- The IDE creates the $PROJECTHOME/MyHello project folder. The project folder
contains all of your sources and project metadata, such as the project Ant
script. The application itself is displayed in the Flow Design window of
the Visual Mobile Designer.
Editing the Java Source Code
Now let's edit the
text displayed by the MIDlet.
- Under HelloMIDlet.java click Screen to switch to the
Screen View displaying the Device Screen, which is the only screen
available in the application.
- Click the Hello World! message in the Device Screen. In
the Properties window click the Hello World! text to change the welcome message text and press
Enter. In this example we typed Make my day.
- The Screen View displays a preview of the
text you enter in the Text field.
Compiling and Running the Project
- Choose Run > Run Project
(MyHello) from the
main IDE's toolbar. Follow the progress of the project compilation in the
Output window. Note that the HelloMIDlet.java file is built before it is
executed. A device emulator opens to display the results of the executed
MIDlet. The device emulator launches the MIDlet and displays the text you
entered in the source code.
You
can specify the emulator to run the MIDlet on by right-clicking the project
node and selecting Run With.. from the
contextual menu. The JavaMEPhone1 available in
Java ME SDK 3.4 is shown below.
- In the emulator window, choose
Application > Exit to close the MIDlet and the emulator window.
