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[[File:icon-Java.png|64x64px||link=|alt=Java]]Java is a modern, object-oriented programming language developed by Oracle.
{{#seo:|description=Learn how to use Phidget USB devices with Java.}}
[[Category:Language]]


__TOC__
==Get Started==
With the Phidget22 library, it's easy to create Java applications that work with Phidget devices.


==Introduction==
==Java Libraries==


{{LanguageSupport|Java|the complete Phidget API, including events|all Phidget devices.|the [[#Javac | {{Code|javac}}]] command line compiler as well as in integrated development environments(IDEs) such as [[#NetBeans | NetBeans]] and [[#Eclipse | Eclipse]]|}}
===Source Files===
The Phidget22 Java library source files are available [https://cdn.phidgets.com/downloads/phidget22/libraries/windows/Phidget22-windevel.zip here].


==Quick Downloads==
==Development Environment Configuration==


Just need the Java documentation, drivers, libraries, and examples?  Here they are:
Before choosing a development environment, make sure you have the [http://www.oracle.com/technetwork/java/index.html Java Development Kit] installed.  
 
===Documentation===
*[http://www.phidgets.com/documentation/JavaDoc.zip API Manual]
 
===Example Code===
*[http://www.phidgets.com/downloads/examples/JavaJNI_2.1.8.20111220.zip Example Code]
 
===Libraries and Drivers===
*[http://www.phidgets.com/downloads/libraries/phidget21jar_2.1.8.20111220.zip phidget21.jar]
*[http://www.phidgets.com/downloads/libraries/Phidget-x86_2.1.8.20111220.exe 32-bit Windows Drivers Installer]
*[http://www.phidgets.com/downloads/libraries/Phidget-x64_2.1.8.20111220.exe 64-bit Windows Drivers Installer]
*[http://www.phidgets.com/downloads/libraries/libphidget_2.1.8.20111028.tar.gz Linux Source]
*[http://www.phidgets.com/downloads/libraries/Phidget_2.1.8.20111103.dmg General Mac OS X Drivers Installer]
 
==Getting started with Java==
 
If you are new to writing code for Phidgets, we recommend starting by running, then modifying existing examples. This will allow you to:
{{ExampleCodeReasons}}
 
Instructions are divided up by operating system. Choose:
*[[#Windows(2000/XP/Vista/7)|Windows 2000 / XP / Vista / 7]]
*[[#Mac OS X |Mac OS X]]
*[[#Linux | Linux]] (including PhidgetSBC)
 
==Windows(2000/XP/Vista/7)==
 
===Description of Library Files===
Java programs on Windows depend on two files, which the installers in the [[#Libraries and Drivers | Quick Downloads]] section put onto your system:
* <b>{{Code|phidget21.dll}}</b> contains the actual Phidgets library, which is used at run-time.  By default, it is placed in {{Code|C:\Windows\System32}}. 
* <b>{{Code|phidget21.jar}}</b> is the Phidgets Java library for JDK <i><b>1.4.2</b></i> or higher. Your compiler has to know where this file is. By default, it is placed into {{Code|C:\Program Files\Phidgets}}. So, you can either point your compiler to that location, or copy and link to it in a directory for your project workspace. For more information, please see the section for your specific compiler/environment.
 
If you do not want to use our installer, you can download the [http://www.phidgets.com/downloads/libraries/phidget21-x86_2.1.8.20110615.zip {{Code|phidget21.dll}}] as well as the [http://www.phidgets.com/downloads/libraries/phidget21jar_2.1.8.20120131.zip {{Code|phidget21.jar}}] and manually install them where you want; refer to our [[Manual Installation Instructions|Manual Installation Instructions]].
 
Running the examples and writing your own code can be fairly compiler-specific, so we include instructions for each [[#Compilers/Environments | compilers/environments]].
 
==Mac OS X==
 
Java has excellent support on Mac OS X through the Java Compiler.
 
The first step in using Java on Mac is to install the Phidget libraries.  Compile and install them as explained on the [[Device List|getting started guide for your device]].  Then, the [[OS - Mac OS X]] page also describes the different Phidget files, their installed locations, and their roles....
 
Running the examples and writing your own code can be fairly compiler-specific, so we include instructions for each [[#Compilers/Environments | compilers/environments]].
 
==Linux==
 
Java has excellent support on Mac OS X through the Java Compiler.
 
The first step in using Java on Linux is to install the Phidget libraries.  Compile and install them as explained on the main [[OS - Linux | Linux page]].  That Linux page also describes the different Phidget files, their installed locations, and their roles.
 
Running the examples and writing your own code can be fairly compiler-specific, so we include instructions for each [[#Compilers/Environments | compilers/environments]].
 
Things to cover that are not covered below:
*Description of files
**Dependence on libphidget21.so
**Using jar in a manifest (including compiled C header)
*Use of sudo without udev rules installed
*Makefile in examples
**Use and expansion
**Other batch compiling of all examples
*Differences between gcj and openjdk packages
*Compiling lines (e.g. .:phidget21)
*Runtime linking of java file resources
*Mismatch of javac and java versions
**On command line
**On Eclipse (weird error given)
*Some information about IDEs as given below in windows, but also
**Binding netbeans to gcj (not sure if it is possible in openjdk)
**Opening simple examples (not copy and paste)
 
==Compilers/Environments==
 
You can program Phidgets with Java in command line with the {{Code|javac}} compiler as well as in IDEs such as NetBeans and Eclipse. This instructions in this section was written for a Windows environment, but the steps also holds true for Mac OS X and Linux environments.


===Javac===
===Javac===
 
{| style="margin:auto;" class="table-no-border mw-collapsible mw-collapsed"
=====Use Our Examples=====
|+ '''Instructions'''
 
|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 .java program. ||[[Image:Language_java_javac_folder.png|center|350px|link=https://cdn.phidgets.com/docs/images/8/89/Language_java_javac_folder.png]]
Download the [http://www.phidgets.com/downloads/examples/JavaJNI_2.1.8.20111220.zip example] and unpack them into a folder. Here, you can find example programs for all the devices. If you aren't sure what the software example for your device is called, check the software object listed in the [[Device List | Getting Started guide for your device]]. Please only use the simple examples. The full examples are intended for the [[#NetBeans | NetBeans IDE]].
|-
 
|[https://www.phidgets.com/downloads/phidget22/libraries/any/Phidget22Java.zip You can download phidget22.jar here].||  
Ensure that the {{Code|phidget21.jar}} is in the same directory as the source code.
|-
 
|Once you are ready to run your program, enter the following command in the command prompt or terminal:
To compile in Windows command prompt:
<syntaxhighlight>
<div class="source">
javac -classpath .;phidget22.jar example.java
<syntaxhighlight lang=bash>
javac -classpath .;phidget21.jar example.java
</syntaxhighlight>
</div>
The command to compile in a Mac OS X and Linux terminal are slightly different. Rather than prefixing {{Code|phidget21.jar}} with a semi-colon( {{Code|;}} ), a colon( {{Code|:}} ) is used.
<div class="source">
<syntaxhighlight lang=bash>
javac -classpath .:phidget21.jar example.java
</syntaxhighlight>
</div>
This will create Java bytecode in the form of {{Code|.class}} files. On Windows, type the following to run the program:
<div class="source">
<syntaxhighlight lang=bash>
java -classpath .;phidget21.jar example
</syntaxhighlight>
</div>
 
On Mac OS X and Linux, type:
<div class="source">
<syntaxhighlight lang=bash>
java -classpath .:phidget21.jar example
</syntaxhighlight>
</div>
 
 
If you wish, you can compile the project as a {{Code|.jar}} so there are fewer files to maintain. The [[http://www.oracle.com/java Java SDK]] provides the {{Code|jar}} utility which packages all the {{Code|.class}} files into a single {{Code|.jar}} file.
To begin, you will have to provide a Manifest file to indicate the program entry point. With your favourite text editor, create a new file with the following content:
<div class="source">
<syntaxhighlight lang=text>
Manifest-Version: 1.0
Class-Path: phidget21.jar
Main-Class: example
</syntaxhighlight>
<br/>
</div> 
Ensure that the file ends in a single new line or a carriage return character.
Save the file as {{Code|example.mf}} and place it in the same directory as the other {{Code|.class}} files.
Next, create the .{{Code|jar}} with:
<div class="source">
<syntaxhighlight lang=bash>
jar -cfm example.jar example.mf *.class
</syntaxhighlight>
</div>
Afterwards, you can run the {{Code|.jar}} with:
<div class="source">
<syntaxhighlight lang=bash>
java -jar example.jar
</syntaxhighlight>
</syntaxhighlight>
</div>
Finally, enter the following command to run the program:
Once you have the Java examples running, we have a [[#Follow The Examples|teaching]] section below to help you follow them.
<syntaxhighlight>
 
java -classpath .;phidget22.jar example
=====Write Your Own Code=====
 
When you are building a project from scratch, or adding Phidget function calls to an existing project, you'll need to configure your development environment to properly link the Phidget Java libraries. Please see the [[#Use Our Examples| previous]] section for instructions.
 
In your code, you will need to include the Phidget library:
 
<div class="source">
<syntaxhighlight lang=java>
import com.phidgets.*;
import com.phidgets.event.*;
</syntaxhighlight>
</syntaxhighlight>
</div>
||
|-
|}


The project now has access to the Phidget21 function calls and you are ready to begin coding.
===Netbeans===
 
{| style="margin:auto;" class="table-no-border mw-collapsible mw-collapsed"
The same [[#Follow The Examples|teaching]] section which describes the examples also has further resources for programming your Phidget.
|+ '''Instructions'''
 
|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 .java program.  ||[[Image:Language_java_javac_folder.png|center|350px|link=https://cdn.phidgets.com/docs/images/8/89/Language_java_javac_folder.png]]
===NetBeans===
|-
 
|[https://www.phidgets.com/downloads/phidget22/libraries/any/Phidget22Java.zip You can download phidget22.jar here].||  
 
|-
=====Use Our Examples=====
| To start, open NetBeans and create a new project. Select Java Application and follow the steps as directed by Netbeans.|| [[Image:Windows_netbeans1.jpg|center|350px|link=https://cdn.phidgets.com/docs/images/c/c9/Windows_netbeans1.jpg]]
 
|-
You first download the [http://www.phidgets.com/downloads/examples/JavaJNI_2.1.8.20111220.zip examples], unpack them into a folder, and then find the source code for your device. The source file will be named the same as the software object for your device. If you aren't sure what the software example for your device is called, check the software object listed in the [[Device List | Getting Started guide for your device]]. The full examples were written in NetBeans, so the rest of this section will use these examples. To use the simple examples, you will have to import the source code into a new NetBeans project.
| Next, add a reference to phidget22.jar by right-clicking on the libraries folder. || [[Image:Windows_netbeans2.jpg|center|350px|link=https://cdn.phidgets.com/docs/images/2/2b/Windows_netbeans2.jpg]]
 
|-
[[File:Java NetBeans Open Project.PNG|link=|alt=Open Project]]
| Navigate to the folder where you downloaded phidget22.jar, and select it. || [[Image:Windows_netbeans3.jpg|center|350px|link=https://cdn.phidgets.com/docs/images/7/76/Windows_netbeans3.jpg]]
 
|-
The only thing left to do is to run the examples! Click on Run &rarr; Run Project. The project, by default tries to find the {{Code|phidget21.jar}} in {{Code|..\..\lib}}.
| The project now has access to Phidgets. ||
 
|}
[[File:Java NetBeans Run.PNG‎|link=|alt=Run]]
 
Once you have the Java examples running, we have a [[#Follow The Examples|teaching]] section below to help you follow them.
 
=====Write Your Own Code=====
 
When you are building a project from scratch, or adding Phidget function calls to an existing project, you'll need to configure your development environment to properly link the Phidget Java libraries. To begin:
 
1. Create a new Java application project with a descriptive name such as PhidgetTest.  
 
[[File:Java NetBeans New Project.PNG|link=|alt=New Project]]
 
2. Add a reference to the Phidgets Java library. In the projects pane, right click {{Code|Libraries}} and add the {{Code|jar}}.
 
[[File:Java NetBeans Add Jar.PNG|link=|alt=Add Jar]]
 
3. Find and select {{Code|phidget21.jar}}.
 
[[File:Java NetBeans Add Jar 2.PNG|link=|alt=Add Jar]]
 
4. Then, in your code, you will need to include the Phidget library:
 
<div class="source">
<syntaxhighlight lang=java>
import com.phidgets.*;
import com.phidgets.event.*;
</syntaxhighlight>
</div>
 
 
The project now has access to the Phidget21 function calls and you are ready to begin coding.
 
The same [[#Follow The Examples|teaching]] section which describes the examples also has further resources for programming your Phidget.


===Eclipse===
===Eclipse===
{| style="margin:auto;" class="table-no-border mw-collapsible mw-collapsed"
|+ '''Instructions'''
|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 .java program.  ||[[Image:Language_java_javac_folder.png|center|350px|link=https://cdn.phidgets.com/docs/images/8/89/Language_java_javac_folder.png]]
|-
|[https://www.phidgets.com/downloads/phidget22/libraries/any/Phidget22Java.zip You can download phidget22.jar here].||
|-
| To start, open Eclipse and create a new Java project.|| [[Image:Windows_eclipse1.jpg|center|350px|link=https://cdn.phidgets.com/docs/images/3/3a/Windows_eclipse1.jpg]]
|-
| On the Libraries tab, click Add External JARs and add phidget22.jar to your project as an external jar. || [[Image:Windows_eclipse2.jpg|center|350px|link=https://cdn.phidgets.com/docs/images/0/0c/Windows_eclipse2.jpg]]
|-
| Create a new Class in your project. || [[Image:Windows_eclipse3.jpg|center|350px|link=https://cdn.phidgets.com/docs/images/d/d9/Windows_eclipse3.jpg]]
|-
| Name the class, and be sure to check the '''public static void main''' box. || [[Image:Windows_eclipse4.jpg|center|350px|link=https://cdn.phidgets.com/docs/images/8/87/Windows_eclipse4.jpg]]
|-
| Your project now has access to Phidgets! ||
|-
|}


=====Use Our Examples=====
=== PhidgetSBC Web Interface ===
 
{| style="margin:auto;" class="table-no-border mw-collapsible mw-collapsed"
1. Download the [http://www.phidgets.com/downloads/examples/JavaJNI_2.1.8.20111220.zip examples] and unpack them into a folder. Here, you can find example programs for all the devices. If you aren't sure what the software example for your device is called, check the software object listed in the [[Device List | Getting Started guide for your device]]. Please use the simple examples. The full examples were written in NetBeans, and are not compatible with Eclipse. The rest of this guide will assume that the simple examples are used. The example source code will be copied into your Eclipse project later on. Keep note of the file name of the example as a Java class will be created with the same name.
|+'''Instructions'''
 
|<center>{{#ev:youtube|gZmWvWXICIA|rel=0}}</center>  
2. Generate a new Java project with a descriptive name such as PhidgetTest. Click next.
|}
 
[[File:Java Eclipse New Project.PNG|link=|alt=New Project]]
 
3. On the next screen, go to the libraries panel and add an external {{Code|jar}}.
 
[[File:Java Eclipse Add Jar 1.PNG|link=|alt=Add Jar]]
 
4. Find and select {{Code|phidget21.jar}}.
 
[[File:Java Eclipse Add Jar 2.PNG|link=|alt=Add Jar]]
 
5. Add a new Java class to the project.
 
[[File:Java Eclipse New Class.PNG|link=|alt=New Class]]
 
6. Name this class with the same name as the simple example's name.
 
[[File:Java Eclipse New Class 2.PNG|link=|alt=New Class]]
 
7. Copy and paste the example source code over to the class you created.
 
[[File:Java Eclipse Source.PNG|link=|alt=Source Code]]
 
8. The only thing left to do is to run the examples!
 
[[File:Java Eclipse Run.PNG|link=|alt=Run]]
 
 
Once you have the Java examples running, we have a [[#Follow The Examples|teaching]] section below to help you follow them.
 
=====Write Your Own Code=====
 
When you are building a project from scratch, or adding Phidget function calls to an existing project, you'll need to configure your development environment to properly link the Phidget Java libraries. Please see the [[#Use Our Examples 3| Use Our Examples]] section for instructions.
 
In your code, you will need to include the Phidget library:
 
<div class="source">
<syntaxhighlight lang=java>
import com.phidgets.*;
import com.phidgets.event.*;
</syntaxhighlight>
</div>
 
The project now has access to the Phidget21 function calls and you are ready to begin coding.
 
The same [[#Follow The Examples|teaching]] section which describes the examples also has further resources for programming your Phidget.
 
==Follow The Examples==
 
By following the instructions for your operating system and compiler above, you probably now have a working example and want to understand it better so you can change it to do what you want.  This teaching section has resources for you to learn from the examples and write your own.
 
Next, comes our API information.  These resources outline the Phidgets Java methods:
 
{{UsingAPhidgetInCodeGeneral|both of which are available in Java|[http://www.phidgets.com/documentation/JavaDoc.zip Java API]}}


===Example Flow===
==Example Code==
Navigate to our [https://www.phidgets.com/?view=code_samples&lang=Java Code Sample Generator] to view and download code samples that are tailored to your specific device.


{{ExamplePseudocode|In Java, you can name these '''event''' functions whatever you like. You will then pass them as function pointers to the Phidget library below in the Main Code section.  This hooks them into the actual events when they occur. <br>
[[Image:Language_java_codesample.png|center|600px|link=https://cdn.phidgets.com/docs/images/a/af/Language_java_codesample.png]]
In the example code, the event functions common to all Phidgets are called things like '''AttachHandler()''' and '''DetachHandler()''', etc.<br><br>
Some event functions will be specific to each device, like when a tag is read on an RFID board, or when a sensor value changes on an Interface Kit.
Other functions are given in the examples to show you more detail on using your Phidget.  For example, '''DeviceInitialize()''' will show what needs to be set up for your Phidget before using it.
|Creating a Phidget software object in Java is specific to the Phidget.  For a Phidget Spatial, for example, this would involve creating a {{Code|SpatialPhidget}} object.  The examples show how to do this and other API functions.<br><br>
The object provides device specific methods which are available from the API for your specific Phidget.|
[http://www.phidgets.com/documentation/JavaDoc.zip Java API]}}


==Common Problems and Solutions/Workarounds==
===Phidget Programming Basics===
{{PhidgetProgrammingBasicsLink}}


Here you can put various frequent problems and our recommended solutions.
==API==
[{{SERVER}}/?view=api&lang=Python Phidget22 API]

Latest revision as of 22:38, 12 March 2026


Get Started

With the Phidget22 library, it's easy to create Java applications that work with Phidget devices.

Java Libraries

Source Files

The Phidget22 Java library source files are available here.

Development Environment Configuration

Before choosing a development environment, make sure you have the Java Development Kit installed.

Javac

Instructions
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 .java program.
Language java javac folder.png
You can download phidget22.jar here.
Once you are ready to run your program, enter the following command in the command prompt or terminal: 
javac -classpath .;phidget22.jar example.java

Finally, enter the following command to run the program: 

java -classpath .;phidget22.jar example

Netbeans

Instructions
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 .java program.
Language java javac folder.png
You can download phidget22.jar here.
To start, open NetBeans and create a new project. Select Java Application and follow the steps as directed by Netbeans.
Windows netbeans1.jpg
Next, add a reference to phidget22.jar by right-clicking on the libraries folder.
Windows netbeans2.jpg
Navigate to the folder where you downloaded phidget22.jar, and select it.
Windows netbeans3.jpg
The project now has access to Phidgets.

Eclipse

Instructions
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 .java program.
Language java javac folder.png
You can download phidget22.jar here.
To start, open Eclipse and create a new Java project.
Windows eclipse1.jpg
On the Libraries tab, click Add External JARs and add phidget22.jar to your project as an external jar.
Windows eclipse2.jpg
Create a new Class in your project.
Windows eclipse3.jpg
Name the class, and be sure to check the public static void main box.
Windows eclipse4.jpg
Your project now has access to Phidgets!

PhidgetSBC Web Interface

Instructions

Example Code

Navigate to our Code Sample Generator to view and download code samples that are tailored to your specific device.

Language java codesample.png

Phidget Programming Basics

To learn more about the structure of the example code, visit our Phidget Programming Basics guide.

API

Phidget22 API

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