Welcome!

Java IoT Authors: Pat Romanski, Liz McMillan, Elizabeth White, Stackify Blog, Carmen Gonzalez

Related Topics: Java IoT, Industrial IoT, Microservices Expo, Microsoft Cloud, Machine Learning , Agile Computing

Java IoT: Blog Feed Post

Building a Simple Peer-to-Peer WebSocket App – Part 1

A Step-by-Step Tutorial

This tutorial series walks you through the simple steps of building an HTML5 WebSocket app, demonstrating the power of the publish/subscribe development pattern directly in JavaScript. Our sample is almost as simple as a Chat app, the “Hello World” app of the WebSocket world, but is a tad more visual and dynamic.

After trying out the completed application, you can either jump in the code and play with it right away, or move on to Part 2 (coming soon) of this tutorial for a step-by-step guide.

About the Environment
This tutorial requires a WebSocket server. We will use http://tutorial.kaazing.com, which hosts the JMS Edition of Kaazing WebSocket Gateway, Kaazing’s high-performance enterprise-grade WebSocket Server. All you’ll need to do is create a WebSocket connection to this server directly from your browser and start “talking” (read: send messages) to it from your browser. On the client side, you can use any modern browser, supported by JSFiddle (learn more about JSFiddle).

Getting Started
First, to understand how the tutorial environment in JSFiddle works, open up the completed demo in JSFiddle. If you’re using a tablet or a smart phone, use the full page mode of the demo.

JSFiddle provides a simple, integrated environment to edit the source of your web pages and apps. It has four panes:

  • Top-left: HTML code (very minimal HTML code in our demo)
  • Bottom-left: JavaScript code
  • Top-right: CSS code (empty in our case)
  • Bottom-right: Result

In the bottom right pane, you can interact with the completed app. Using the slider, you can change the size of the image. Now, open another browser window, pointing to the same JSFiddle demo URL. You can also use a tablet or a smart phone. Position your two browser windows side-by-side. As you adjust the slider in the bottom-right pane, right above the image in one browser window, the slider position and image size change in the other one. They’re kept in sync.

The browsers are communicating with the WebSocket gateway which is running in Amazon’s EC2 cloud, hosted in North Virginia, USA. When you move the slider, messages travel from your browser, to the WebSocket gateway, and back to the other browser.

Watch this video demonstrating the completed application (if the letters are blurry, switching the video to HD helps):

At this point, you can make any changes to the application. Click the Run button to test out your changes. To roll back to the original state, simply reload the original JSFiddle demo URL.

Note: If you see the image resize without you moving the slider, there’s a chance that somebody else is experimenting with the tutorial as well. To ensure that you’re not interfering with anybody else, change the topic name to something unique to you, for example by appending your name. Locate the following line in the bottom-left pane, towards the top of the file:

 

var TOPIC_NAME = "/topic/myTopic";

 

Modify the name of the topic. For example:

 

var TOPIC_NAME = "/topic/PeterTopic";

Test your code by clicking the Run button.

As another test, you can also change the application’s logging behavior. To give it a try, change the value of the IN_DEBUG_MODE variable to false, located in the bottom-left pane towards the top of the file. Original line:

var IN_DEBUG_MODE = true;

After the changes:

var IN_DEBUG_MODE = false;

Test your code by clicking the Run button.

In Part 2 (coming soon) you can learn about the demo code and how quickly and easily you can build real-time web applications with Web messaging.

Read the original blog entry...

More Stories By Kaazing Blog

Kaazing is helping define the future of the event-driven enterprise by accelerating the Web for the Internet of Things.

@ThingsExpo Stories
The 21st International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Digital Transformation, Machine Learning and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding busin...
Internet of @ThingsExpo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 21st International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. @ThingsExpo Silicon Valley Call for Papers is now open.
As cloud adoption continues to transform business, today's global enterprises are challenged with managing a growing amount of information living outside of the data center. The rapid adoption of IoT and increasingly mobile workforce are exacerbating the problem. Ensuring secure data sharing and efficient backup poses capacity and bandwidth considerations as well as policy and regulatory compliance issues.
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm.
SYS-CON Events announced today that SoftLayer, an IBM Company, has been named “Gold Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. SoftLayer, an IBM Company, provides cloud infrastructure as a service from a growing number of data centers and network points of presence around the world. SoftLayer’s customers range from Web startups to global enterprises.
Five years ago development was seen as a dead-end career, now it’s anything but – with an explosion in mobile and IoT initiatives increasing the demand for skilled engineers. But apart from having a ready supply of great coders, what constitutes true ‘DevOps Royalty’? It’ll be the ability to craft resilient architectures, supportability, security everywhere across the software lifecycle. In his keynote at @DevOpsSummit at 20th Cloud Expo, Jeffrey Scheaffer, GM and SVP, Continuous Delivery Busine...
SYS-CON Events announced today that Outscale will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Outscale's technology makes an automated and adaptable Cloud available to businesses, supporting them in the most complex IT projects while controlling their operational aspects. You boost your IT infrastructure's reactivity, with request responses that only take a few seconds.
SYS-CON Events announced today that Loom Systems will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Founded in 2015, Loom Systems delivers an advanced AI solution to predict and prevent problems in the digital business. Loom stands alone in the industry as an AI analysis platform requiring no prior math knowledge from operators, leveraging the existing staff to succeed in the digital era. With offices in S...
SYS-CON Events announced today that DivvyCloud will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. DivvyCloud software enables organizations to achieve their cloud computing goals by simplifying and automating security, compliance and cost optimization of public and private cloud infrastructure. Using DivvyCloud, customers can leverage programmatic Bots to identify and remediate common cloud problems in rea...
SYS-CON Events announced today that Tintri, Inc, a leading provider of enterprise cloud infrastructure, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Tintri offers an enterprise cloud platform built with public cloud-like web services and RESTful APIs. Organizations use Tintri all-flash storage with scale-out and automation as a foundation for their own clouds – to build agile development environments...
SYS-CON Events announced today that Progress, a global leader in application development, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Enterprises today are rapidly adopting the cloud, while continuing to retain business-critical/sensitive data inside the firewall. This is creating two separate data silos – one inside the firewall and the other outside the firewall. Cloud ISVs ofte...
SYS-CON Events announced today that Tappest will exhibit MooseFS at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. MooseFS is a breakthrough concept in the storage industry. It allows you to secure stored data with either duplication or erasure coding using any server. The newest – 4.0 version of the software enables users to maintain the redundancy level with even 50% less hard drive space required. The software func...
SYS-CON Events announced today that Interoute has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Interoute is the owner operator of Europe's largest network and a global cloud services platform, which encompasses over 70,000 km of lit fiber, 15 data centers, 17 virtual data centers and 33 colocation centers, with connections to 195 additional partner data centers. Our full-service Unifie...
SYS-CON Events announced today that EARP will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. "We are a software house, so we perfectly understand challenges that other software houses face in their projects. We can augment a team, that will work with the same standards and processes as our partners' internal teams. Our teams will deliver the same quality within the required time and budget just as our partn...
SYS-CON Events announced today that Carbonite will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Carbonite protects your entire IT footprint with the right level of protection for each workload, ensuring lower costs and dependable solutions with DoubleTake and Evault.
SYS-CON Events announced today that Super Micro Computer, Inc., a global leader in compute, storage and networking technologies, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Supermicro (NASDAQ: SMCI), the leading innovator in high-performance, high-efficiency server technology, is a premier provider of advanced server Building Block Solutions® for Data Center, Cloud Computing, Enterprise IT, Hadoop/...
SYS-CON Events announced today that Technologic Systems Inc., an embedded systems solutions company, will exhibit at SYS-CON's @ThingsExpo, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Technologic Systems is an embedded systems company with headquarters in Fountain Hills, Arizona. They have been in business for 32 years, helping more than 8,000 OEM customers and building over a hundred COTS products that have never been discontinued. Technologic Systems’ pr...
SYS-CON Events announced today that Progress, a global leader in application development, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Enterprises today are rapidly adopting the cloud, while continuing to retain business-critical/sensitive data inside the firewall. This is creating two separate data silos – one inside the firewall and the other outside the firewall. Cloud ISVs oft...
SYS-CON Events announced today that Cloudistics, an on-premises cloud computing company, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Cloudistics delivers a complete public cloud experience with composable on-premises infrastructures to medium and large enterprises. Its software-defined technology natively converges network, storage, compute, virtualization, and management into a ...
New competitors, disruptive technologies, and growing expectations are pushing every business to both adopt and deliver new digital services. This ‘Digital Transformation’ demands rapid delivery and continuous iteration of new competitive services via multiple channels, which in turn demands new service delivery techniques – including DevOps. In this power panel at @DevOpsSummit 20th Cloud Expo, moderated by DevOps Conference Co-Chair Andi Mann, panelists will examine how DevOps helps to meet th...