Welcome!

Java IoT Authors: Plutora Blog, Elizabeth White, Liz McMillan, Yeshim Deniz, Jyoti Bansal

Related Topics: Java IoT

Java IoT: Article

Under the Hood of a J2EE Application Server

Under the Hood of a J2EE Application Server

I recently had the opportunity to talk with many Java users about the current release and their general experiences with the platform. One of those developers told me that he didn't use J2SE but his J2EE VM sometimes caused problems.

Now most of you know that there is no such thing as a J2EE JVM. From my own experience with J2EE application servers, many do a good job hiding this from you. It can be difficult to work out which version of J2SE you are using, let alone know that J2SE is behind the scenes.

In this issue we are focusing on J2EE. If you are a core J2SE developer, there are some great tips and techniques that apply equally to J2SE and J2EE.

As a quick refresh, the J2SE platform contains the Java runtime and many of the core libraries that are used in your J2EE application. The Java runtime also contains client-side classes such as Swing. If those classes are not referenced by your application (which is normally the case), then they're not loaded at runtime. To compile Java programs use the javac compiler, which can be redistributed with the Java runtime and is also available in the Java developer kit.

One of the key technologies is the core XML library. In J2SE 5.0, the JAXP 1.3 library is bundled and includes support for XML 1.1, DOM Level 3, and SAX 2.0.2.

One new library in J2SE 5.0 that should be familiar to you is the addition of the Java Management Extension, JMX. JMX has been used in J2EE to monitor and manage J2EE applications using MBeans. The JMX framework has been extended in J2SE 5.0 with a remote interface and also has some system MBeans and a mini MBeanServer that can be used to monitor low memory conditions. This same monitoring information is published via the SNMP protocol as well.

The other side of monitoring is application profiling. The core technology here has been JVMPI, the Java profiling interface. JVMPI is still supported in J2SE 5.0 but is superseded by the new JVM TI tools interface, which provides finer-grained and less intrusive profiling. Your existing profiling tools will require updates to support the JVM TI interface, but the benefits of improved profiling will repay the investment in newer tools.

The support for network-aware distributed objects is also provided in J2SE using technologies such as RMI, JNDI, and CORBA. There have been minor increments in J2SE 5.0 for each of these technologies. One change that makes J2EE developers' coding a little easier is that RMI no longer needs a separate stub creation step.

The Java language changes, of course, apply to J2SE and J2EE and the same javac compiler is used to build both types of applications. Later releases of J2EE will be able to take advantage of features like metadata to automate many tasks, including generating deployment descriptors.

For those developers who use JavaServer Pages, the newer javac compiler will work as before. There was a proposal to increase the maximum method length due to some side effects from some of the early JSP implementations. The 64K restriction still exists but modern JSP compilers no longer run into that barrier.

Another area that is easy to overlook is database access. The JDBC framework is again delivered in J2SE. In J2SE 5.0 the addition of implementations for disconnected rowsets allows you to pass rows from your database and manipulate them without needing to maintain a live database connection. This technology even allows you to convert the database results to XML, provide updates using XML, and then resynchronize those changes at a later time.

It shouldn't be a surprise that the Java runtime is also responsible for the compilation of bytecodes and the threading framework. Many existing J2EE application servers provide support for a thread pool. In J2SE 5.0 the concurrency library also provides a choice of user space thread pools, which are portable across application servers.

J2EE application servers will also be able to provide more control over worker thread tasks by taking advantage of the new future tasks.

What does this mean for J2EE application developers? Well, regardless of the frameworks you use, J2SE 5.0 is going to bring two waves of improvements.

The first wave is updates to the libraries, such as XML, that are used by J2EE in the core platform. The second wave is to then exploit the advantages of the new features by the J2EE 5.0 platform and its components. I'm sure you'll agree that there is plenty to look forward to whether you consider yourself a J2EE developer, J2SE developer, or both.

More Stories By Calvin Austin

A section editor of JDJ since June 2004, Calvin Austin is an engineer at SpikeSource.com. He previously led the J2SE 5.0 release at Sun Microsystems and also led Sun's Java on Linux port.

Comments (1) View Comments

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.


Most Recent Comments
noname 12/30/04 01:16:53 PM EST

With a title like Whats under the hood of a J2EE AppServer I was expecting some system-level details about J2EE AppServers...not whats new in JDK5

@ThingsExpo Stories
Apache Hadoop is emerging as a distributed platform for handling large and fast incoming streams of data. Predictive maintenance, supply chain optimization, and Internet-of-Things analysis are examples where Hadoop provides the scalable storage, processing, and analytics platform to gain meaningful insights from granular data that is typically only valuable from a large-scale, aggregate view. One architecture useful for capturing and analyzing streaming data is the Lambda Architecture, represent...
My team embarked on building a data lake for our sales and marketing data to better understand customer journeys. This required building a hybrid data pipeline to connect our cloud CRM with the new Hadoop Data Lake. One challenge is that IT was not in a position to provide support until we proved value and marketing did not have the experience, so we embarked on the journey ourselves within the product marketing team for our line of business within Progress. In his session at @BigDataExpo, Sum...
Things are changing so quickly in IoT that it would take a wizard to predict which ecosystem will gain the most traction. In order for IoT to reach its potential, smart devices must be able to work together. Today, there are a slew of interoperability standards being promoted by big names to make this happen: HomeKit, Brillo and Alljoyn. In his session at @ThingsExpo, Adam Justice, vice president and general manager of Grid Connect, will review what happens when smart devices don’t work togethe...
SYS-CON Events announced today that Ocean9will 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. Ocean9 provides cloud services for Backup, Disaster Recovery (DRaaS) and instant Innovation, and redefines enterprise infrastructure with its cloud native subscription offerings for mission critical SAP workloads.
In his session at @ThingsExpo, Eric Lachapelle, CEO of the Professional Evaluation and Certification Board (PECB), will provide an overview of various initiatives to certifiy the security of connected devices and future trends in ensuring public trust of IoT. Eric Lachapelle is the Chief Executive Officer of the Professional Evaluation and Certification Board (PECB), an international certification body. His role is to help companies and individuals to achieve professional, accredited and worldw...
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 CA Technologies has been named “Platinum 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, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business – from apparel to energy – is being rewritten by software. From ...
The taxi industry never saw Uber coming. Startups are a threat to incumbents like never before, and a major enabler for startups is that they are instantly “cloud ready.” If innovation moves at the pace of IT, then your company is in trouble. Why? Because your data center will not keep up with frenetic pace AWS, Microsoft and Google are rolling out new capabilities In his session at 20th Cloud Expo, Don Browning, VP of Cloud Architecture at Turner, will posit that disruption is inevitable for c...
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 ...
The explosion of new web/cloud/IoT-based applications and the data they generate are transforming our world right before our eyes. In this rush to adopt these new technologies, organizations are often ignoring fundamental questions concerning who owns the data and failing to ask for permission to conduct invasive surveillance of their customers. Organizations that are not transparent about how their systems gather data telemetry without offering shared data ownership risk product rejection, regu...
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 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.
SYS-CON Events announced today that CrowdReviews.com has been named “Media 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. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buyers...
SYS-CON Events announced today that T-Mobile 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. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
SYS-CON Events announced today that Infranics 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. Since 2000, Infranics has developed SysMaster Suite, which is required for the stable and efficient management of ICT infrastructure. The ICT management solution developed and provided by Infranics continues to add intelligence to the ICT infrastructure through the IMC (Infra Management Cycle) based on mathemat...
SYS-CON Events announced today that SD Times | BZ Media has been named “Media 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. BZ Media LLC is a high-tech media company that produces technical conferences and expositions, and publishes a magazine, newsletters and websites in the software development, SharePoint, mobile development and commercial UAV markets.
SYS-CON Events announced today that Telecom Reseller has been named “Media 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. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
"I think that everyone recognizes that for IoT to really realize its full potential and value that it is about creating ecosystems and marketplaces and that no single vendor is able to support what is required," explained Esmeralda Swartz, VP, Marketing Enterprise and Cloud at Ericsson, in this SYS-CON.tv interview at @ThingsExpo, held June 7-9, 2016, at the Javits Center in New York City, NY.
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
SYS-CON Events announced today that HTBase 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. HTBase (Gartner 2016 Cool Vendor) delivers a Composable IT infrastructure solution architected for agility and increased efficiency. It turns compute, storage, and fabric into fluid pools of resources that are easily composed and re-composed to meet each application’s needs. With HTBase, companies can quickly prov...