Using a Raspberry Pi to Deploy JavaFX Applications

1. Insert the SD card into your computer, or connect it to your computer by using an SD card peripheral.

2. Start the SD Formatter tool and click Option.

   

3. In the Option Setting dialog box, select FULL (Overwrite) from Format Type and ON from Format Size Adjustment, and then click OK.

   

4. Click Format to start the SD Formatter tool.

   

5. Click OK to format the SD memory card.

   

   A dialog box displays the progress of the format.

   

6. When the format is completed, click OK to close the dialog box.

   

7. Click Exit to close the SD Formatter tool.

   

You are now ready to install the Raspbian Wheezy image in the SD memory card. Leave the card in the computer.

1. Make a note of the SHA-1 checksum for the zip file that you downloaded.

   

   Note: The SHA-1 checksum may also be in a file with a .sha1 extension.

2. Open a command window in the directory where you downloaded the zip file and enter sha1sum.exe 2013-09-10-wheezy-raspbian.zip.

   

   Note: If the SHA-1 checksum does not match the checksum listed on the download page, try downloading the zip file again.

3. Unzip 2013-09-10-wheezy-raspbian.zip with your favorite unzip tool.

4. Start the Win32DiskImager application. Make sure that the device address is the same as the mount point for the SD memory card.

   

5. Click the folder button, navigate to the location of the image file, and then click Write.

   

6. Click Yes to confirm that you want to overwrite the contents of the SD memory card.

   

   A progress meter is displayed.

   

7. When the Write Successful message is displayed, click OK.

   

8. Click Exit to close Win32 Disk Imager.

   

9. Remove the SD memory card from the computer.

You are now ready to boot the Raspberry Pi and install the JDK 8 distribution for Pi.

1. Perform the following steps:

   1. Insert the SD memory card into the Raspberry Pi.
   2. Connect the USB keyboard and USB mouse.
   3. Connect the HDMI display.
   4. Connect the Ethernet cable.
   5. Plug in the power cable.

   

2. Select setup option 1, Expand Filesystem, and press Enter to expand the file system and use all of the SD memory card storage.

   

3. Press Enter to close the confirmation screen.

   

1. Press the up or down arrow key to select option 4, Internationalisation Options, and press Enter.

   

2. Press the up or down arrow key to select option I2, Change Timezone, and press Enter.

   

3. Press the up or down arrow key to select your country and press Enter.

   

4. Press the up or down arrow key to select the time zone in your country (if applicable) and press Enter.

   

1. Press the up or down arrow key to select option 8, Advanced Options, and press Enter.

   

2. Press the up or down arrow key to select option A4, SSH, and press Enter.

   

3. Press the left or right arrow key to select Enable and press Enter.

   

4. Press Enter.

   

5. Press the left or right arrow key to select Finish and press Enter.

   

6. Press the left or right arrow key to select Yes and then press Enter to reboot the Raspberry Pi.

   

   The Raspberry Pi reboots.

   

   Notice the line that indicates the IP address of the Raspberry Pi.

At this point, you can disconnect the HMDI monitor, the USB mouse, and the USB keyboard.

1. Start putty.exe and perform the following steps:

   1. On the boot screen, enter the IP address in the IP address field.
   2. Enter Raspberry SSH in the Saved Sessions field.
   3. Click Save.

   

2. Click Open.

   

3. Click Yes to accept the security alert.

   

4. Enter pi as the login name and raspberry as the password.

   

If you plan to use your Raspberry Pi on a wireless network, skip this section.

1. In a separate command-prompt window, enter ipconfig to get the netmask and default gateway for your network.

   

   Note: If you are using a wireless connection, the information appears under the Wireless LAN adapter heading.

2. In a PuTTY window, enter sudo nano /etc/network/interfaces and then perform the following steps:

   1. Comment out the iface eth0 inet dhcp line.
   2. Below that, add the iface eth0 inet static line.
   3. Use your network settings to add the IP, network, netmask, broadcast, and gateway addresses. For example:
      address 192.168.1.105 should be similar to the IPv4 address.
      network 192.168.1.0 should be the network prefix and zeroes.
      netmask 255.255.255.0 should match the subnet mask.
      broadcast 192.168.1.255 should be the network broadcast address.
      gateway 192.168.1.1 should match the default gateway.
      

   

   

3. Press Ctrl + O and then press Enter to write the file.

   

4. Press Ctrl + X and then press Enter to close nano and return to the prompt.

5. Enter sudo reboot to reboot the Raspberry Pi and make the changes.

   

If you plan to use a wireless USB module with your Raspberry Pi, you need to edit the network interfaces file.

1. In a PuTTY window, enter sudo nano /etc/network/interfaces and then perform the following steps:

   1. Comment out the following lines: allow-hotplug wlan0
      iface wlan0 inet manual
      wpa-roam /etc/wpa_spplicant/wpa_supplicant.conf
   2. Below that, add the following lines: auto wlan0
      iface wlan0 inet static
   3. Use your network settings to add the IP address, network mask, and gateway address. For example:
      address 192.168.1.105
      netmask 255.255.255.0
      gateway 192.168.1.1
   4. Add the network SSID and passkey for your network in double quotation marks. For example:
      wpa-ssid "mynetwork"
      wpa-psk "cants@y"

   

2. Press Ctrl + O and then press Enter to write the file. Press Ctrl + X to exit nano.

3. Enter sudo halt to halt the Raspberry Pi.

   

4. Unplug the power cable to the Raspberry Pi.

5. The Raspberry Pi supports only two USB connections. To use the USB Wifi module, unplug the USB mouse, the USB keyboard, and the Ethernet cable, and then plug in the USB Wifi module.

   To use JavaFX applications, you need a mouse and preferably a keyboard. You can use a USB hub to connect everything to the Raspberry Pi.

   

6. Plug the power cable into the Raspberry Pi.

1. To reconnect to the Raspberry Pi, right-click in the header of the PuTTY window and select Restart Session.

   

2. Enter pi as the login name and raspberry as the password.

   

1. Launch the PSFTP tool and then perform the following steps:

   1. Enter open 192.168.1.105.
   2. Enter pi as the login name and raspberry as the password.

   

2. Enter lcd C:\Temp to change the local directory to the location of JDK 8 for Linux ARMv6/7.

   

3. Enter put jdk-8-ea-b124-linux-arm-vfp-hflt-17_jan_2014.tar.gz.

   

4. Type exit to quit the PSFTP tool.

   

1. In the PuTTY window, enter tar -xvf jdk-8-ea-b124-linux-arm-vfp-hflt-17_jan_2014.tar.gz to extract JDK 8.

   

   If a message indicates that some files have a timestamp, perform the following steps to correct the error:

   1. Enter rm jdk1.8.0 -Rf to remove the JDK.
   2. Enter sudo date -s "28 JAN 2014 17:00:00" to set the new system date, replace the date with the current date.
   3. Try the step again. Enter tar -xvf jdk-8-ea-b124-linux-arm-vfp-hflt-17_jan_2014.tar.gz to uncompress the JDK8 without problems.

2. Enter sudo update-alternatives --install /usr/bin/java java /home/pi/jdk1.8.0/bin/java 1.

   

3. Enter sudo update-alternatives --set java /home/pi/jdk1.8.0/bin/java.

   

4. Enter nano .profile.

   

5. At the bottom of the file, add the following:

   JAVA_HOME="/home/pi/jdk1.8.0"
   export JAVA_HOME
   PATH="$JAVA_HOME/bin:$PATH"

   

6. Press Ctrl + O and then press Enter to save the changes. Press Ctrl + X to exit nano.

   

1. In the PuTTY window, enter sudo visudo.

   

2. Enter Defaults env_keep +="JAVA_HOME" after all the Defaults declarations.

   

3. Press Ctrl + O and then press Enter to save the changes. Press Ctrl + X to exit nano.

   

1. Enter sudo reboot to restart the Raspberry Pi. Wait a couple of seconds to let the Raspberry Pi reboot.

   

2. Right-click in the header of the PuTTY window and select Restart Session to reconnect to the Raspberry Pi.

   

3. Enter pi as the user name and raspberry as the password.

   

4. Enter java -version to see the current Java version that is being used.

   

5. Enter javac -version to see the current Java compiler version that is being used.

   

6. Enter sudo java -version to see the Java version that is being used by the root user.

   

1. In NetBeans, select File > New Project.

   

2. Select JavaFX from Categories and JavaFX Application from Projects and click Next.

   

3. Enter BasicFX as the project name, select a location for the project, and click Finish.

   

   Your project is created and loaded into the IDE, and you can explore the contents of the project.

4. Right-click the project and select Clean and Build to generate a distributable JAR file.

   

5. Click Select Class in the Browse JavaFX Application Classes if the dialog box is displayed.

   

   The Output tab shows the progress and indicates when the process is completed.

   

6. Open a File Explorer window and locate the project folder.

   

7. Open the dist folder and locate the BasicFX.jar file

   

8. Copy the BasicFX.jar file to c:\Temp to make it easier to upload to the Raspberry Pi.

   

The NetBeans IDE includes sample applications that you can create and modify to showcase Java technologies. In this section, you create a JavaFX clock application by using one of these templates.

1. In NetBeans, select File > New Project.

   

2. Select Samples > JavaFX from Categories and DigitalClock from Projects and click Next.

   

3. Set a location for the project and click Finish.

   

   The project is created with the code required to display a digital clock using JavaFX.

4. Right-click the project, select Clean and Build, and wait until the project is built.

   

5. Open a File Explorer window, browse to the DigitalClock project folder, and open the dist folder.

   

6. Copy the DigitalClock.jar file to the c:\Temp folder to make it easier to deploy it on the Raspberry Pi.

   

1. Launch the PSFTP tool and then perform the following steps:

   1. Enter open 192.168.1.105.
   2. Enter pi as the login name and raspberry as the password.

   

2. Perform the following steps to transfer the JavaFX application JAR files:

   1. Enter lcd C:\Temp to change the local directory to the location of the JDK 8 for Linux ARMv6/7.
   2. Enter put BasicFX.jar.
   3. Enter put DigitalClock.jar.

   

3. Type exit to quit the PSFTP tool.

The applications are deployed on the Raspberry Pi.

1. In a PuTTY window, enter sudo halt and wait for the LEDs to stop blinking.

   

2. When only the PWR LED is on, unplug the power cable from the Pi.

   

3. Connect the video cable, mouse, and keyboard to the Raspberry Pi, and then connect the power cable.

   

4. In the Pi, log in as the user pi with the password raspberry.

   

5. Enter java -jar BasicFX.jar.

   

   The application is displayed on the Raspberry Pi screen.

   

JavaFX applications are displayed on the main screen of the Raspberry Pi, but you can start and stop them from a remote console, which is useful when debugging or when the application cannot be stopped. In some cases, you can stop applications by pressing Ctrl + C. If the application doesn't stop, use the method outlined in this section.

1. On your Desktop PC, open a PuTTY window and log in to the Raspberry as the user pi with the password raspberry.

2. Enter ps ax | grep java and locate the process ID of the BasicFX.jar application.

   

3. Enter sudo kill -9 2326 and replace 2326 with the process ID from the previous step.

   

   Notice that the JavaFX application stops.

   

You can use this method whenever you cannot shut down an application normally and you need to forcefully stop it.

1. In the PuTTY window, enter java -jar DigitalClock.jar.

   

   The Digital Clock application starts and runs in full screen mode.

   

2. In the PuTTY window, press Ctrl + C to stop the application.