Template:PT3 JAVA LNX JAVAC

Language - Java

Linux with Javac

Welcome to using Phidgets with Java! By using Java, you will have access to the complete Phidget22 API, including events.

Javac is a command line-based compiler for java programs that compiles java code into bytecode class files.

Requirements

First, make sure you have the following installed:

● Phidgets Drivers for Linux

● The Java Development Kit from Oracle

● A copy of phidget22.jar

Setting UDev Rules

By default, Linux will not allow regular users to access physical hardware, as a security feature. This means that you must grant yourself root privileges via sudo to run Phidgets code.

sudo java -classpath .:phidget22.jar example

To avoid having to use sudo every time, you can set up a rules file to allow it automatically using the vendor code for Phidget USB devices. Create a text file called 99-libphidget22.rules containing the following line:

SUBSYSTEMS=="usb", ACTION=="add", ATTRS{idVendor}=="06c2", ATTRS{idProduct}=="00[3-a][0-f]", MODE="666"

Mode 666 means every user has permission to read and write to the specified devices. Next, move this file to /etc/udev/rules.d. Now you can run code that uses Phidgets as a regular user without sudo.

Installing Java

In order to use Java, you will need to download and install the JDK. You can do this by entering the following command in the terminal (where VERSION is replaced with your preferred version number):

apt-get install openjdk-VERSION-jdk

Before continuing, ensure your JDK version matches your JRE version:

javac -version

java -version

Finding Code Samples

To find the code sample to use for your Phidget, navigate to the Code Samples page and select your device from the drop-down menu.

Once you select your device, the code sample generator will give you a working code sample, and a selection of options to customize it to your needs.

Using the Code Samples

If it's unclear what any of the options do, click on the nearby '?' for more info.

Once you've made your selections, click the Download Example button to download a sample Java file.

Setting up a New Project

Whether you are running our examples or adding Phidget functionality to an existing project, you'll need to configure your development environment to properly link the Phidget Java library.

The easiest way to allow Java to access the Phidgets Java library is to place a copy of phidget22.jar in the same folder as your program:

Compile and Run

Once you are ready to run your program, open the terminal at the folder location. Next, enter the following command in the terminal:

javac -classpath .:phidget22.jar example.java

Finally, enter the following command to run the program:

java -classpath .:phidget22.jar example

The project is now using Phidgets!

What's Next?

Now that you've set up Phidgets in your programming environment, you should read our guide on Phidget Programming Basics to learn the fundamentals of programming with Phidgets.

«

»