Welcome!

Java IoT Authors: Elizabeth White, Yeshim Deniz, Pat Romanski, Liz McMillan, Frank Lupo

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 JVMPI is still supported in J2SE 5.0 but is superseded by the new JVM TI tools interface, which provides finer-grained and less intrusive profiling.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
Enterprises have taken advantage of IoT to achieve important revenue and cost advantages. What is less apparent is how incumbent enterprises operating at scale have, following success with IoT, built analytic, operations management and software development capabilities – ranging from autonomous vehicles to manageable robotics installations. They have embraced these capabilities as if they were Silicon Valley startups. As a result, many firms employ new business models that place enormous impor...
SYS-CON Events announced today that SourceForge has been named “Media Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. SourceForge is the largest, most trusted destination for Open Source Software development, collaboration, discovery and download on the web serving over 32 million viewers, 150 million downloads and over 460,000 active development projects each and every month.
SYS-CON Events announced today that Dasher Technologies will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Dasher Technologies, Inc. ® is a premier IT solution provider that delivers expert technical resources along with trusted account executives to architect and deliver complete IT solutions and services to help our clients execute their goals, plans and objectives. Since 1999, we'v...
As popularity of the smart home is growing and continues to go mainstream, technological factors play a greater role. The IoT protocol houses the interoperability battery consumption, security, and configuration of a smart home device, and it can be difficult for companies to choose the right kind for their product. For both DIY and professionally installed smart homes, developers need to consider each of these elements for their product to be successful in the market and current smart homes.
SYS-CON Events announced today that MIRAI Inc. will exhibit at the Japan External Trade Organization (JETRO) Pavilion at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. MIRAI Inc. are IT consultants from the public sector whose mission is to solve social issues by technology and innovation and to create a meaningful future for people.
SYS-CON Events announced today that Massive Networks, that helps your business operate seamlessly with fast, reliable, and secure internet and network solutions, has been named "Exhibitor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. As a premier telecommunications provider, Massive Networks is headquartered out of Louisville, Colorado. With years of experience under their belt, their team of...
SYS-CON Events announced today that TidalScale, a leading provider of systems and services, will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. TidalScale has been involved in shaping the computing landscape. They've designed, developed and deployed some of the most important and successful systems and services in the history of the computing industry - internet, Ethernet, operating s...
Widespread fragmentation is stalling the growth of the IIoT and making it difficult for partners to work together. The number of software platforms, apps, hardware and connectivity standards is creating paralysis among businesses that are afraid of being locked into a solution. EdgeX Foundry is unifying the community around a common IoT edge framework and an ecosystem of interoperable components.
Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, will discuss how from store operations...
In a recent survey, Sumo Logic surveyed 1,500 customers who employ cloud services such as Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP). According to the survey, a quarter of the respondents have already deployed Docker containers and nearly as many (23 percent) are employing the AWS Lambda serverless computing framework. It’s clear: serverless is here to stay. The adoption does come with some needed changes, within both application development and operations. Tha...
SYS-CON Events announced today that IBM has been named “Diamond Sponsor” of SYS-CON's 21st Cloud Expo, which will take place on October 31 through November 2nd 2017 at the Santa Clara Convention Center in Santa Clara, California.
In his Opening Keynote at 21st Cloud Expo, John Considine, General Manager of IBM Cloud Infrastructure, will lead you through the exciting evolution of the cloud. He'll look at this major disruption from the perspective of technology, business models, and what this means for enterprises of all sizes. John Considine is General Manager of Cloud Infrastructure Services at IBM. In that role he is responsible for leading IBM’s public cloud infrastructure including strategy, development, and offering ...
Infoblox delivers Actionable Network Intelligence to enterprise, government, and service provider customers around the world. They are the industry leader in DNS, DHCP, and IP address management, the category known as DDI. We empower thousands of organizations to control and secure their networks from the core-enabling them to increase efficiency and visibility, improve customer service, and meet compliance requirements.
Join IBM November 1 at 21st Cloud Expo at the Santa Clara Convention Center in Santa Clara, CA, and learn how IBM Watson can bring cognitive services and AI to intelligent, unmanned systems. Cognitive analysis impacts today’s systems with unparalleled ability that were previously available only to manned, back-end operations. Thanks to cloud processing, IBM Watson can bring cognitive services and AI to intelligent, unmanned systems. Imagine a robot vacuum that becomes your personal assistant tha...
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend 21st Cloud Expo October 31 - November 2, 2017, at the Santa Clara Convention Center, CA, and June 12-14, 2018, at the Javits Center in New York City, NY, and learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
Recently, REAN Cloud built a digital concierge for a North Carolina hospital that had observed that most patient call button questions were repetitive. In addition, the paper-based process used to measure patient health metrics was laborious, not in real-time and sometimes error-prone. In their session at 21st Cloud Expo, Sean Finnerty, Executive Director, Practice Lead, Health Care & Life Science at REAN Cloud, and Dr. S.P.T. Krishnan, Principal Architect at REAN Cloud, will discuss how they b...
SYS-CON Events announced today that mruby Forum will exhibit at the Japan External Trade Organization (JETRO) Pavilion at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. mruby is the lightweight implementation of the Ruby language. We introduce mruby and the mruby IoT framework that enhances development productivity. For more information, visit http://forum.mruby.org/.
Digital transformation is changing the face of business. The IDC predicts that enterprises will commit to a massive new scale of digital transformation, to stake out leadership positions in the "digital transformation economy." Accordingly, attendees at the upcoming Cloud Expo | @ThingsExpo at the Santa Clara Convention Center in Santa Clara, CA, Oct 31-Nov 2, will find fresh new content in a new track called Enterprise Cloud & Digital Transformation.
SYS-CON Events announced today that NetApp has been named “Bronze Sponsor” of SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. NetApp is the data authority for hybrid cloud. NetApp provides a full range of hybrid cloud data services that simplify management of applications and data across cloud and on-premises environments to accelerate digital transformation. Together with their partners, NetApp emp...
SYS-CON Events announced today that Avere Systems, a leading provider of enterprise storage for the hybrid cloud, will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Avere delivers a more modern architectural approach to storage that doesn't require the overprovisioning of storage capacity to achieve performance, overspending on expensive storage media for inactive data or the overbui...