Language - Java

Java is a modern, object-oriented programming language developed by Oracle.

Introduction

If this is your first time working with a Phidget, we suggest starting with the Getting Started page for your specific device. This can be found in the user guide for your device. That page will walk you through installing drivers and libraries for your operating system, and will then bring you back here to use Java specifically.

Java is capable of using the complete Phidget API, including events. We also provide example code in Java for all Phidget devices.

Java can be developed with various environments such as javac, NetBeans, and Eclipse.{{{5}}}

You can compare Java with our other supported languages.

Quick Downloads

Just need the Java drivers, libraries, and examples? Here they are:

Java API Documentation:

• C# API Manual Download or (HTML online version)
• General API (more help on functions common to all Phidgets)
• Device Specific APIs (more help on functions specific to your Phidget)

Java Example Code:

• Java Example Code

Libraries and Drivers:

• phidget21.jar
• 32 bit Windows (drivers, with libraries)
• 64 bit Windows (drivers, with libraries)
• General Linux Libraries ( Linux Library Setup Instructions)
• General Mac OSX Libraries ( Mac OS X Library Setup Instructions)

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:

• Make sure your libraries are properly linked
• Go from source code to a test application as quickly as possible
• Ensure your Phidget is hooked up properly

Instructions are divided up by operating system. Choose:

• Windows 2000 / XP / Vista / 7
• Mac OS X
• Linux (including PhidgetSBC)

Windows(2000/XP/Vista/7)

Libraries

• phidget21.jar

Description

Java programs on Windows depend on the following files, which the installers above put onto your system:

• phidget21.dll contains the actual Phidgets library, which is used at run-time. If you used our installer, it's already correctly placed in C:\Windows\System32. It can be manually installed - check our Manual Installation instructions.

You will also need one of the following two files, depending on the .NET framework version you are targeting:

• phidget21.jar is the Phidgets library for JDK 1.4.2 or higher. Your compiler has to know where this file is. By default, our installer puts this file into 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 get the file here.

Running the examples and writing your own code can be fairly compiler-specific, so we include instructions for each compiler below.

NetBeans

Please start by downloading the Java Examples. The full examples were written in NetBeans. But Eclipse will easily open it.

• Java Examples

Use Our Examples

To run the examples, you first download them from above and unpack them into a folder. To load all projects in Visual Studio, go to File | Open | Project, and open AllExamples/AllExamples.sln or AllExamples/AllExamples_vs2008.sln for Visual Studio 2005 and 2008, respectively.

If you are opening the Phidget examples in Visual Studio 2010, you will need to go through the Visual Studio Conversion Wizard to convert the 2005 or 2008 project.

This will load all of the examples available for C#, and then you can set your main project to be the one that matches your device. If you aren't sure what the software example for your device is called, check the software object listed in the Getting Started guide for your device.

The only thing left to do is to run the examples! Click on Debug -> Start Debugging. Please note that the projects, by default try to find the Phidget21.NET.dll in the C:\Program Files\Phidgets. If you have it installed in another location, please change the path accordingly. If you are receiving an error message regarding that the namespace Phidgets cannot be found, please re-add the reference to Phidget21.NET.dll. Please see the next section for details.



Once you have the C# examples running, we have a 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 compiler / development environment to properly link the Phidget C# libraries. To begin:

• Generate a new Visual C# Windows Applications project with a descriptive name such as PhidgetTest.

• Add a reference to the .NET Phidgets lilbrary.

• Under the .NET tab, select Phidget21.NET.dll.

If you used our installer, these files are installed in C:\Program Files\Phidgets, by default. If it does not appear in this list, then you can browse to the Phidget Framework installation directory and add the file.

Then, in your code, you will need to include the Phidget library:

  using Phidgets;
  using Phidgets.Events;

The project now has access to the Phidget21 function calls and you are ready to begin coding.

The same teaching section which describes the examples also has further resources for programming your Phidget.

Java

This section will provide instructions on how to compile using the javac compiler. Start by downloading the Java Examples.

• Java Examples

Use Our Examples

Download the examples from above 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 Getting Started guide for your device. Please only use the simple examples.
Ensure that the phidget21.jar is in the same directory as the source code.

To compile:
File:Java Compile.PNG

This will create Java bytecode in the form of .class files. Type the following to run the program:
File:Java Run.PNG

If you wish, you can compile the project as a .jar so fewer files have to maintain. The [Java SDK] provides the jar utility which packages all the .class files into a single .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:

Manifest-Version: 1.0
Class-Path: phidget21.jar
Main-Class: example
 

Ensure that the file ends in a new line or a carriage return. Save the file as example.mf and place it in the same directory as the other .class files. Next, create the .jar with:

File:Java Create Jar.PNG

Afterwards, you can run the .jar with:

File:Java Create Run Jar.PNG

Once you have the Java examples running, we have a 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 compiler / development environment to properly link the Phidget C# libraries. Please see the previous section for instructions.

In your code, you will need to include the Phidget library:

  import com.phidgets.*;
  import com.phidgets.event.*;

The project now has access to the Phidget21 function calls and you are ready to begin coding.

The same teaching section which describes the examples also has further resources for programming your Phidget.

Eclipse

Start by downloading the C# Examples. These examples were written in Visual Studio 2005 and 2008, but are also compatible with MonoDevelop.

• C# Eamples

Use Our Examples

Download the examples from above 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 Getting Started guide for your device. If you are running under the .NET framework, you can use either the full or simple examples. Otherwise, if you are running under the Mono framework, please only use the simple examples. The full examples uses Windows Forms, which is not completely compatible with Mono's Gtk#.

To run the examples, you first download them from above and unpack them into a folder. To load all projects in MonoDevelop, go to File | Open, and open AllExamples/AllExamples.sln

This will load all of the examples available for C#, and then you can set your main project to be the one that matches your device. If you aren't sure what the software example for your device is called, check the software object listed in the Getting Started guide for your device.

The only thing left to do is to run the examples! Right click the project, and click on Run With and select the target framework. Please note that the projects, by default try to find the Phidget21.NET.dll in the C\Program Files\Phidgets. If you have it installed in another location, please change the path accordingly. If you are receiving an error message regarding that the namespace Phidgets cannot be found, please re-add the reference to Phidget21.NET.dll. Please see the next section for details.

Once you have the C# examples running, we have a 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 compiler / development environment to properly link the Phidget C# libraries. To begin:

• Create a new C# empty project with a descriptive name such as PhidgetTest.

• Add a reference to the .NET library.

• Select Phidget21.NET.dll. If you used our installer, by default, this file is placed in C:\Program Files\Phidgets. If it is in another location, please change the path accordingly.

Then, in your code, you will need to include the Phidget library:

  using Phidgets;
  using Phidgets.Events;

The project now has access to the Phidget21 function calls and you are ready to begin coding.

The same teaching section which describes the examples also has further resources for programming your Phidget.

Mac OS X

C# has excellent support on Mac OS X through the Mono framework.

The first step in using C# on Mac is to install the Phidget libraries. Compile and install them as explained on the 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....

Linux

C# has support on Linux through the Mono framework.

The first step in using C# on Linux is to install the Phidget libraries. Compile and install them as explained on the main Linux page. That Linux page also describes the different Phidget files, their installed locations, and their roles.

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 C# Phidget functions:

• C# API (This is the complete set of functions you have available for all Phidgets)
• Device Specific APIs - The one for your Phidget can be found in its user guide.

To learn the details behind opening, configuring, using, and closing your Phidget, try the General Phidget Programming page. That page also describes using the Phidget in an event-driven manner and in a traditional manner, both of which are available in C#.

Example Flow

The Hello World example has this general structure so you can follow along. We also have an in-depth general introduction to writing Phidget code (like open, read data, etc), as well as the C# API for specific syntax:

// ----- Event and Other Functions ----- Create any Language-Specific Functions (exception handling) Create General Attach, Detach, and Error Handling Functions: On attach: Print Hello Message On detach: Print Goodbye Message		In C#, 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. In the example code, the event functions common to all Phidgets are called things like AttachHandler() and DetachHandler(), etc. 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.
// ----- Main Code ----- Create Manager Software Object Hook Event Functions created above to Device Open Device Wait for 'Enter' key character input Handle on-going attach and detach events Print Hello and Goodbye messages Exit upon input Close Device Delete Device		Creating a Phidget software object in C# is specific to the Phidget. For a Phidget Spatial, for example, this would involve creating a Spatial object. The examples show how to do this and other API functions. The object provides device specific methods and properties which are available from the API for your specific Phidget.

Common Problems and Solutions/Workarounds

Here you can put various frequent problems and our recommended solutions.