Welcome!

Weblogic Authors: Yeshim Deniz, Elizabeth White, Michael Meiner, Michael Bushong, Avi Rosenthal

Related Topics: Java IoT, Weblogic

Java IoT: Blog Feed Post

Closing Applications (Correctly) in JDeveloper

We've identified the symptoms of the problem and the associated workaround

The following documents a somewhat small issue we're having with JDeveloper 11.1.1.2.0. At this time I'm unable to lodge an SR with Oracle Support as we don't understand the circumstances under which it occurs, thus we can't build the usual simple "Hello World" test case that Support so thrives on. However as we've identified the symptoms of the problem and the associated workaround I'll publish them here for others to benefit (including my team) so we don't hit the issue again.

Note this issue is only verified under JDev 11.1.1.2.0. I have no knowledge if the issue can be replicated in other JDev versions as this stage.

Issue Symptoms
From time to time after checking out an application from SVN inside JDeveloper:



....we'd discover JDev has incidentally modified one of the project files. In the following example the ViewController project is italicized meaning it has been modified:


Pressing "Save all" and then comparing the modified file against the previous revision reveals that the ViewController project has reverted back to the default settings, losing all the changes from the previous ViewController revision:


With the ViewController modified, the project can no longer compile (because among other things it's lost the attached libraries), and the change is effectively destructive. Whatever you do, don't check the ViewController project file back into SVN as it's just plain wrong.

Workaround #1
If you've arrived at this point where a project has been automatically modified by JDeveloper when checked out of SVN, the workaround in this situation is to Revert the project file back to the previous revision.

A Known Unknown Bug
In the example above I've identified the issue with a ViewController project in an ADF application. However note this problem isn't specific to any project type (e.g. Model, ViewController, whatever). We've experienced this issue across different projects in different applications from time to time. The converse of this issue is there's been a whole lot of projects this issue doesn't occur for too (i.e. in the above example, the Model project wasn't incidentally modified too), so the problem has something to do with the specific project configuration where the error occurs. Unfortunately we're unsure what that specific configuration is. However once the problem is detected it is consistently replicable on the problematic project at hand.

Bug Preconditions
While we haven't been able to work out what configuration in the project files causes the bug, we are aware of a set of steps that do lead up to the bug.

From a day by day basis our programmers will have an application open in JDeveloper, synced with an SVN repository:


From time to time the programmer makes a decision that rather than syncing each individual file change coming from the SVN repository into the application, it's just easier to delete the local working copy of the application and check out a whole brand new copy. To do this the developer:

a) Closes JDeveloper
b) Identifies the working copy application directory on the filesystem
c) Deletes it
d) Opens JDeveloper
e) Checks out the same application from the SVN Repository into the *same* directory that the previous working copy was checked out

It's at this point we see the issue described, but as mentioned, not for all application projects, just some projects, sometimes. However once this problem occurs, repeating steps "a" to "e" from above the issue is consistently reproducible.

From what we can see for step "e" is if we check out to any other directory, the problem isn't replicated.

What we found odd about this issue is if another developer on another machine checks out the same application, the said problematic project file wouldn't be automatically modified by JDeveloper. Yet this gave us the spark of an idea of what's going wrong and how to avoid it in the first place.

Workaround #2
You'll note in the "a" to "e" description above, the developer closes JDev, then deletes the application from the file system, then re-opens JDev. What we're not giving the JDev IDE here is a chance to recognize that one of the applications it had opened has been removed completely from the file system.

The IDE seems to be partially smart in that the application is removed from the application poplist at the top of the Application Navigator when we reopen JDeveloper. Yet if we then proceed to check out the same application as described in "a" to "e" we hit the described problem.

A workaround to the problem is before closing the JDev IDE, via the Application menu selecting Close, to close the selected application. If this option is done first the end problem is not seen. The conclusion is this gives JDev a chance to tidy up it's internal state about which applications and projects are open, and somehow this avoids the bug we're experiencing.

Arguably the IDE should be able to handle this situation regardless. The fact that the bug is destructive to the project configuration is a major concern, especially if a junior programmer doesn't understand what's happening and checks in the changed project file regardless, but in the end following the workaround steps here avoid the issue in the first place.

Read the original blog entry...

More Stories By Chris Muir

Chris Muir, an Oracle ACE Director, senior developer and trainer, and frequent blogger at http://one-size-doesnt-fit-all.blogspot.com, has been hacking away as an Oracle consultant with Australia's SAGE Computing Services for too many years. Taking a pragmatic approach to all things Oracle, Chris has more recently earned battle scars with JDeveloper, Apex, OID and web services, and has some very old war-wounds from a dark and dim past with Forms, Reports and even Designer 100% generation. He is a frequent presenter and contributor to the local Australian Oracle User Group scene, as well as a contributor to international user group magazines such as the IOUG and UKOUG.

@ThingsExpo Stories
Large industrial manufacturing organizations are adopting the agile principles of cloud software companies. The industrial manufacturing development process has not scaled over time. Now that design CAD teams are geographically distributed, centralizing their work is key. With large multi-gigabyte projects, outdated tools have stifled industrial team agility, time-to-market milestones, and impacted P&L stakeholders.
Gemini is Yahoo’s native and search advertising platform. To ensure the quality of a complex distributed system that spans multiple products and components and across various desktop websites and mobile app and web experiences – both Yahoo owned and operated and third-party syndication (supply), with complex interaction with more than a billion users and numerous advertisers globally (demand) – it becomes imperative to automate a set of end-to-end tests 24x7 to detect bugs and regression. In th...
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
"There's plenty of bandwidth out there but it's never in the right place. So what Cedexis does is uses data to work out the best pathways to get data from the origin to the person who wants to get it," explained Simon Jones, Evangelist and Head of Marketing at Cedexis, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"Akvelon is a software development company and we also provide consultancy services to folks who are looking to scale or accelerate their engineering roadmaps," explained Jeremiah Mothersell, Marketing Manager at Akvelon, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, 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 buye...
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, 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.
"Space Monkey by Vivent Smart Home is a product that is a distributed cloud-based edge storage network. Vivent Smart Home, our parent company, is a smart home provider that places a lot of hard drives across homes in North America," explained JT Olds, Director of Engineering, and Brandon Crowfeather, Product Manager, at Vivint Smart Home, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
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, discussed how from store operations and ...
It is of utmost importance for the future success of WebRTC to ensure that interoperability is operational between web browsers and any WebRTC-compliant client. To be guaranteed as operational and effective, interoperability must be tested extensively by establishing WebRTC data and media connections between different web browsers running on different devices and operating systems. In his session at WebRTC Summit at @ThingsExpo, Dr. Alex Gouaillard, CEO and Founder of CoSMo Software, presented ...
WebRTC is great technology to build your own communication tools. It will be even more exciting experience it with advanced devices, such as a 360 Camera, 360 microphone, and a depth sensor camera. In his session at @ThingsExpo, Masashi Ganeko, a manager at INFOCOM Corporation, introduced two experimental projects from his team and what they learned from them. "Shotoku Tamago" uses the robot audition software HARK to track speakers in 360 video of a remote party. "Virtual Teleport" uses a multip...
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, whic...
SYS-CON Events announced today that Evatronix 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. Evatronix SA offers comprehensive solutions in the design and implementation of electronic systems, in CAD / CAM deployment, and also is a designer and manufacturer of advanced 3D scanners for professional applications.
Leading companies, from the Global Fortune 500 to the smallest companies, are adopting hybrid cloud as the path to business advantage. Hybrid cloud depends on cloud services and on-premises infrastructure working in unison. Successful implementations require new levels of data mobility, enabled by an automated and seamless flow across on-premises and cloud resources. In his general session at 21st Cloud Expo, Greg Tevis, an IBM Storage Software Technical Strategist and Customer Solution Architec...
To get the most out of their data, successful companies are not focusing on queries and data lakes, they are actively integrating analytics into their operations with a data-first application development approach. Real-time adjustments to improve revenues, reduce costs, or mitigate risk rely on applications that minimize latency on a variety of data sources. In his session at @BigDataExpo, Jack Norris, Senior Vice President, Data and Applications at MapR Technologies, reviewed best practices to ...
An increasing number of companies are creating products that combine data with analytical capabilities. Running interactive queries on Big Data requires complex architectures to store and query data effectively, typically involving data streams, an choosing efficient file format/database and multiple independent systems that are tied together through custom-engineered pipelines. In his session at @BigDataExpo at @ThingsExpo, Tomer Levi, a senior software engineer at Intel’s Advanced Analytics gr...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things’). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing? IoT is not about the devices, it’s about the data consumed and generated. The devices are tools, mechanisms, conduits. In his session at Internet of Things at Cloud Expo | DXWor...