Industrial IoT Authors: Yeshim Deniz, Liz McMillan, Lori MacVittie, Pat Romanski, Elizabeth White

Related Topics: Industrial IoT

Industrial IoT: Article

When Should Java And XML Be Used For Messaging?

When Should Java And XML Be Used For Messaging?

When does it make sense to use JMS (Java Message Service) and XML to support a heterogeneous messaging environment? Most buzzword-compliant people talk about JMS and XML when thinking about developing a messaging solution for their organization.

While in most cases this is the correct answer, we need to understand the requirements we're trying to fulfill before giving an answer. For example:

  • Can the solution be deployed using asynchronous communications or does it require synchronous behavior?
  • Will the solution be used in the intranet or extranet?
  • What are the messaging paradigms supported by your system?
  • Does the underlying messaging system support JMS?
  • What qualities of service (QoS) are supported by the messaging system?
  • What are the characteristics of the information to be published on the network?
  • Are e-mail messages a requirement?
  • What are the possible messaging systems the solution will be deploying against?
In short, we need to understand the characteristics of the problem before we can justify the use of any technology - in this case JMS and XML. Let me first give a brief introduction to JMS and explain the role of XML. My goal this month is to help you understand the requirements that XML and JMS are attempting to meet.

Sun, IBM, Modulus, NEON, OpenHorizon, Oracle, TIBCO, and Vitria developed the JMS specification. The purpose was to define a common API that would enable Java developers to use the same messaging system. In the JMS specification there's a clear distinction between the application and the message provider layers. The software developer is responsible for coding his or her application against the JMS interfaces; the message provider is responsible for coding the implementation to the interfaces. The idea behind this approach is to decouple the client application from the specifics of the messaging system. This allows the message provider layer to plug into the application layer. JMS defines two types of messaging paradigms:

  • Point-to-point
  • Publish/subscribe
The point-to-point paradigm follows a producer/consumer pattern that allows the producer application to write information to a queue and a consumer application to read it from the queue (see Figure 1). The queue mechanism identifies the decoupling point between the producer application and the consumer application. The producer application doesn't depend on the consumer application to access the queue to write to it, or vice versa. Some messaging systems provide QoS that enables persistence of the information stored inside a queue.

The publish/subscribe paradigm follows an observer pattern with explicit interest defined (see Figure 2). This approach allows subscriber applications to specify the types of events they're interested in receiving and allows the publishing application to broadcast messages independent of interested parties. The mapping between interested subscribers and published content is facilitated by the messaging system. This allows subscribers to publish information totally independent of recipients and vice versa. Some messaging systems provide QoS that enables the persistence of published messages for future processing.

JMS developers are responsible for selecting the message provider and for specifying the type of messaging model they want to implement. In addition, some JMS services are supported by the JMS layer independent of the underlying messaging implementation. These are:

  • Transactions
  • Message filtering
These need to be supported by the JMS provider implementation layer, however.

Most messaging systems, including the JMS specification, are agnostic when it comes to message content. They categorize message content as:

  • Basic types (int, float, char, long, etc.)
  • Text (string)
  • Bytes (byte arrays)
This is where XML comes to the rescue by providing the mechanisms to define the content of a message. This information is used by both sender and receiver clients to manipulate complex objects. The XML tags allow the sender application to serialize an object for future consumption by the receiver application. It's the responsibility of the receiver application to reconstruct the object for further manipulation.

Another advantage of using XML for defining the content of a message is that it provides a platform-independent mechanism for exchanging information between heterogeneous applications. This means a Visual Basic application can package an object using XML and send it to a Java application where it can be reconstructed from the XML message.

It's important to realize that XML doesn't provide a communications transport like TIBCO, MQSeries, IIOP, SMTP, and HTTP. However, it can work with any of these transports to provide message- content abstraction. One example of how XML facilitates the creation of communication transport is the use of HTTP and XML to develop XML RPCs.

Does this mean that the buzzword-compliant people know best? I don't think so! However, they pay enough attention to know what the technologists are saying. As mentioned earlier, JMS provides a communication abstraction layer for messaging while XML provides a message content abstraction layer. JMS enables the use of XML via its TextMessage content type. This enables string-based messages and XML text (see Listing 1).

When JMS and XML?
JMS and XML provide a total abstraction of communications transport and data content. Given this statement, why should you care about any requirements? Isn't this the solution to all your messaging needs? Let's revisit the questions asked earlier:

Q: Can the solution be deployed using asynchronous communications or does it require synchronous behavior?
A: JMS deals with asynchronous communications. If you need to manipulate synchronous flows like RMI, CORBA, or HTTP, you may want to consider using synchronous protocols. While you can implement synchronous behavior with asynchronous protocols, this isn't the norm and it's more difficult.

Q: Will this solution be used in the intranet or extranet?
A: JMS deals with messaging in thje intranet. Publish/subscribe and queue management systems aren't designed to deal with unreliable networks like the Internet. If you want to set up extranet communications, you need to consider XML RPC (SOAP) or SMTP (e-mail).

Q: What are the messaging paradigms supported by your system?
A: Does the underlying system support publish/subscribe or point-to-point? Some systems support only one or the other. Publish/subscribe systems have been optimized for broadcast (e,g., TIBCO). They haven't been optimized for point-to-point. Similarly, queue management systems have been optimized to provide message persistence via queues and point-to-point communications. They haven't been optimized for publish/subscribe.

Q: Does the underlying messaging system support JMS?
A: If your corporate messaging system doesn't support JMS, you may be stuck with their proprietary Java interfaces or you may need to develop your own JNI interfaces.

Q: What QoS are supported by the messaging system?
A: Does the JMS implementation that comes with your messaging system support guaranteed delivery, transactions, and message filtering? If your application requires transactions and your JMS implementation doesn't support them, this may be a problem. You may be forced to evaluate a different JMS provider. If your JMS provider supports message persistence, where is the persistence storage happening, in an RDBMS or proprietary storage? Persistence may be an issue if your JMS provider requires you to purchase a specific RDBMS.

Q: What are the characteristics of the information to be published on the network?
A: If you're using publish/subscribe, what type of information are you publishing? This issue is particularly important if you're using publishing as an event mechanism. Events are normally regarded as lightweight messages. Because of this requirement, it may not make sense to inquire about the overhead of wrapping a simple event value in an XML message. The subscribers may be listening on a topic called shipping orders, and the only content inside the event may be the order number. In this situation there's no need to create an XML message to publish the information. However, if subscribers are listening for the complete order with all of its parameters, it makes sense to package the order object inside an XML message for further processing by the subscriber application.

Q: Are e-mail messages a requirement?
A: JMS doesn't handle e-mail sending or receiving. That's the purpose of the JavaMail APIs. If the application needs to support e-mail for asynchronous messaging, then JMS isn't the answer. However, if your application needs to use an intranet-based messaging system like TIBCO, and you want to implement an e-mail gateway, the combination of JMS and JavaMail is ideal.

Q: What are the possible messaging systems that the solution will be deployed against?
A: If the solution being developed will be used only against one messaging system, it may not make sense to use JMS. This is the case if there's no JMS provider for a particular messaging framework but there is a Java API for that system. However, if the solution can be deployed against multiple messaging systems, it makes sense to leverage a communications abstraction layer.

JMS and XML are an ideal combination and can be deployed to provide a total abstraction solution for messaging and data content. However, you need to understand your requirements clearly before making the technology call. Therefore, it's important to know the limitations and correct usage of the JMS and XML technologies.

More Stories By Israel Hilerio

Israel Hilerio is a program manager at Microsoft in the Windows Workflow Foundation team. He has 15+ years of development experience doing business applications and has a PhD in Computer Science.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

@ThingsExpo Stories
Fact is, enterprises have significant legacy voice infrastructure that’s costly to replace with pure IP solutions. How can we bring this analog infrastructure into our shiny new cloud applications? There are proven methods to bind both legacy voice applications and traditional PSTN audio into cloud-based applications and services at a carrier scale. Some of the most successful implementations leverage WebRTC, WebSockets, SIP and other open source technologies. In his session at @ThingsExpo, Da...
In past @ThingsExpo presentations, Joseph di Paolantonio has explored how various Internet of Things (IoT) and data management and analytics (DMA) solution spaces will come together as sensor analytics ecosystems. This year, in his session at @ThingsExpo, Joseph di Paolantonio from DataArchon, will be adding the numerous Transportation areas, from autonomous vehicles to “Uber for containers.” While IoT data in any one area of Transportation will have a huge impact in that area, combining sensor...
The Internet of Things (IoT), in all its myriad manifestations, has great potential. Much of that potential comes from the evolving data management and analytic (DMA) technologies and processes that allow us to gain insight from all of the IoT data that can be generated and gathered. This potential may never be met as those data sets are tied to specific industry verticals and single markets, with no clear way to use IoT data and sensor analytics to fulfill the hype being given the IoT today.
@ThingsExpo has been named the Top 5 Most Influential M2M Brand by Onalytica in the ‘Machine to Machine: Top 100 Influencers and Brands.' Onalytica analyzed the online debate on M2M by looking at over 85,000 tweets to provide the most influential individuals and brands that drive the discussion. According to Onalytica the "analysis showed a very engaged community with a lot of interactive tweets. The M2M discussion seems to be more fragmented and driven by some of the major brands present in the...
If you had a chance to enter on the ground level of the largest e-commerce market in the world – would you? China is the world’s most populated country with the second largest economy and the world’s fastest growing market. It is estimated that by 2018 the Chinese market will be reaching over $30 billion in gaming revenue alone. Admittedly for a foreign company, doing business in China can be challenging. Often changing laws, administrative regulations and the often inscrutable Chinese Interne...
SYS-CON Events announced today that SoftNet Solutions will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. SoftNet Solutions specializes in Enterprise Solutions for Hadoop and Big Data. It offers customers the most open, robust, and value-conscious portfolio of solutions, services, and tools for the shortest route to success with Big Data. The unique differentiator is the ability to architect and ...
SYS-CON Events announced today that Pulzze Systems will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Pulzze Systems, Inc. provides infrastructure products for the Internet of Things to enable any connected device and system to carry out matched operations without programming. For more information, visit http://www.pulzzesystems.com.
In the next forty months – just over three years – businesses will undergo extraordinary changes. The exponential growth of digitization and machine learning will see a step function change in how businesses create value, satisfy customers, and outperform their competition. In the next forty months companies will take the actions that will see them get to the next level of the game called Capitalism. Or they won’t – game over. The winners of today and tomorrow think differently, follow different...
One of biggest questions about Big Data is “How do we harness all that information for business use quickly and effectively?” Geographic Information Systems (GIS) or spatial technology is about more than making maps, but adding critical context and meaning to data of all types, coming from all different channels – even sensors. In his session at @ThingsExpo, William (Bill) Meehan, director of utility solutions for Esri, will take a closer look at the current state of spatial technology and ar...
The Open Connectivity Foundation (OCF), sponsor of the IoTivity open source project, and AllSeen Alliance, which provides the AllJoyn® open source IoT framework, today announced that the two organizations’ boards have approved a merger under the OCF name and bylaws. This merger will advance interoperability between connected devices from both groups, enabling the full operating potential of IoT and representing a significant step towards a connected ecosystem.
SYS-CON Media announced today that @WebRTCSummit Blog, the largest WebRTC resource in the world, has been launched. @WebRTCSummit Blog offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. @WebRTCSummit Blog can be bookmarked ▸ Here @WebRTCSummit conference site can be bookmarked ▸ Here
SYS-CON Events announced today that Streamlyzer will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Streamlyzer is a powerful analytics for video streaming service that enables video streaming providers to monitor and analyze QoE (Quality-of-Experience) from end-user devices in real time.
You have great SaaS business app ideas. You want to turn your idea quickly into a functional and engaging proof of concept. You need to be able to modify it to meet customers' needs, and you need to deliver a complete and secure SaaS application. How could you achieve all the above and yet avoid unforeseen IT requirements that add unnecessary cost and complexity? You also want your app to be responsive in any device at any time. In his session at 19th Cloud Expo, Mark Allen, General Manager of...
@ThingsExpo has been named the Top 5 Most Influential Internet of Things Brand by Onalytica in the ‘The Internet of Things Landscape 2015: Top 100 Individuals and Brands.' Onalytica analyzed Twitter conversations around the #IoT debate to uncover the most influential brands and individuals driving the conversation. Onalytica captured data from 56,224 users. The PageRank based methodology they use to extract influencers on a particular topic (tweets mentioning #InternetofThings or #IoT in this ...
SYS-CON Events announced today that Super Micro Computer, Inc., a global leader in Embedded and IoT solutions, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 7-9, 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/Big Data, HPC and ...
Cloud based infrastructure deployment is becoming more and more appealing to customers, from Fortune 500 companies to SMEs due to its pay-as-you-go model. Enterprise storage vendors are able to reach out to these customers by integrating in cloud based deployments; this needs adaptability and interoperability of the products confirming to cloud standards such as OpenStack, CloudStack, or Azure. As compared to off the shelf commodity storage, enterprise storages by its reliability, high-availabil...
The IoT industry is now at a crossroads, between the fast-paced innovation of technologies and the pending mass adoption by global enterprises. The complexity of combining rapidly evolving technologies and the need to establish practices for market acceleration pose a strong challenge to global enterprises as well as IoT vendors. In his session at @ThingsExpo, Clark Smith, senior product manager for Numerex, will discuss how Numerex, as an experienced, established IoT provider, has embraced a ...
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at @ThingsExpo, James Kirkland, Red Hat's Chief Arch...
We are reaching the end of the beginning with WebRTC, and real systems using this technology have begun to appear. One challenge that faces every WebRTC deployment (in some form or another) is identity management. For example, if you have an existing service – possibly built on a variety of different PaaS/SaaS offerings – and you want to add real-time communications you are faced with a challenge relating to user management, authentication, authorization, and validation. Service providers will w...
When people aren’t talking about VMs and containers, they’re talking about serverless architecture. Serverless is about no maintenance. It means you are not worried about low-level infrastructural and operational details. An event-driven serverless platform is a great use case for IoT. In his session at @ThingsExpo, Animesh Singh, an STSM and Lead for IBM Cloud Platform and Infrastructure, will detail how to build a distributed serverless, polyglot, microservices framework using open source tec...