David S. Read

As I release my 3rd Alpha-version of Sparql Droid I thought I’d document a few lessons learned and open items as I work with the Android environment.  Some of my constraints are based on targeting smart phones rather than tablets, but the lessons learned around development environments, screen layouts, and memory management are valuable.

I’ll start on the development side.  I use Eclipse and the android development plugin is very helpful. It greatly streamlines the development process.  Principally, it automates the generation of the resources from the source files.  These resources, such as screen layouts and menus, require a conversion step after being edited.  The automation, though, comes at a price.

Taking a step back, Android doesn’t use an Oracle-compliant JVM.  Instead it uses the Dalvik VM.  This difference creates two major ramifications: 1) not all the standard packages are available; and 2) any compiled Java code has to go through a step to “align” it for Dalvik. This alignment process is required for class files you create and for any third-party classes (such as those found in external JAR files).  Going back to item 1, if an external JAR file you use needs a package that isn’t part of Dalvik, you’ll need to recreate it.

The alignment process works pretty fast for small projects.  My first application was a game that used no external libraries.  The time required to compile and align was indistinguishable from typical compile time.  However, with Sparql Droid, which uses several large third-party libraries, the alignment time is significant – on the order of a full minute.

That delay doesn’t sound so bad, unless you consider the Build Automatically feature in Eclipse.  This is a feature that you want to turn off when doing Android development that includes third-party libraries of any significance. Turning off that feature simply adds an extra step to the editing process, a manual build, and slightly reduces the convenience of the environment.

With my first Android project, I was able to edit a resource file and immediately jump back to my Java code and have the resource be recognized.   Now I have to manually do a build (waiting a minute or so) after editing a resource file before it is recognized on the code side.  Hopefully the plug-in will be improved to cache the aligned libraries, saving that time when the libraries aren’t being changed.

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The semantic technology concepts that comprise what is generally called the semantic web involve paradigm shifts in the ways that we represent data, organize information and compute results. Such shifts create opportunities and present challenges.  The opportunities include easier correlation of decentralized information, flexible data relationships and reduced data storage entropy.  The challenges include new data management technology, new syntaxes, and a new separation of data and its relationships.

I am a strong advocate of leveraging semantic technology.  I believe that this new paradigms provide a more flexible basis for our journey to create meaningful, efficient and effective business automation solutions. However, one challenge that differentiates leveraging semantic technology from more common technology (such as relational databases) is the lack of mature tools supporting a business system infrastructure.

It will take a while for solid solutions to appear.  Support for mainstream capabilities such as reporting, BI, workflow, application design and development that all leverage semantic technology are missing or weak at best.  Again, this is an opportunity and a challenge.  For those who enjoy creating computer software it presents a new world of possibilities.  For those looking to leverage mature solutions in order to advance their business vision it will take investment and patience.

In parallel with the semantic paradigm we have an ever increasing focus on mobile-based solutions. Smart phones and tablet devices, focused on network connectivity as the enabler of value, rather than on-board storage and compute power, are becoming the standard tool for human-system interaction.  As we design new solutions we must keep the mobile-accessible mantra in mind.

As part of my exploration of these two technologies, I’ve started working on a semantic technology mobile application called Sparql Droid. Built for the Android platform, my goal is a tool for exploring and mashing semantic data sources.  As a small first-step I’ve leveraged the Androjena port of the Jena framework and created an application with some basic capabilities.

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A few months ago I blogged about my new computer and my quest to use only OpenOffice as my document tool suite (How I Spent My Christmas Vacation).  For a little over a month I was able to work effectively, exchanging documents and spreadsheets with coworkers without incident.  However, it all came crashing down.  My goal in this blog entry is to describe what worked and what didn’t.

OpenOffice provides five key office-type software packages.  Writer for word processing, Calc for spreadsheets, Impress for presentations, Base for database work and Draw for diagrams.  There is a sixth tool, Math for creating scientific formulas and equations, which is similar to the equation editor available with MS Word.

As one of my coworkers suggests when providing positive and negative feedback, I’ll use the sandwich approach.  If you’ve not heard of this approach, the idea is to start with some good points, then go through the issues and wrap up with a positive item or two.

On a positive note, the OpenOffice suite is production worthy.  For the two tools that seem to be most commonly used in office settings, word processing and spreadsheets, the Writer and Calc tools have all the features that I was used to using with the Microsoft Office (MS Office) tools.  In fact for the most part I was unaware that I was using a different word processor or spreadsheet. From a usability perspective there is little or no learning curve for an experienced MS Office user to effectively use these OpenOffice tools.

Of key importance to me was the ability to work with others who were using MS Office.  The ability for OpenOffice to open the corresponding MS Office documents worked well at first but then cracks began to show.

OpenOffice Writer was able to work with MS Office documents in both the classic Word “doc” format and the newer Word 2007 and later “docx” format.  However, Writer cannot save to the “docx” format.  If you open a “docx” then the only MS Office format that can be used to save the document is the “doc” format.  At first this was a small annoyance but obviously meant that if a “docx” feature was used it would be lost on the export to “doc”.

Another aggravating issue was confusion when using the “Record Changes” feature, which is analogous to the “Track Changes” features in MS Word.  Although the updates made using MS Word could be seen in Writer, notes created in Word were inconsistently presented in Writer.  The tracked changes were also somewhat difficult to understand when multiple iterations of edits had occurred.  At work we often use track changes as we collaborate on documentation so this feature needs to work well for our team.

I eventually ran into two complete show-stoppers.  In the first case, OpenOffice was unable to display certain images embedded in an MS Word document.  Although some images had previously been somewhat distorted, it turned out that certain types of embedded images wouldn’t display at all.  The second issue involved the Impress (presentation) tool.

I’ve mentioned that Writer and Calc are very mature and robust.  The Impress tool doesn’t seem to be as solid.  As I began working with a team member on a presentation we were delivering in February I discovered that there appears to be little compatibility between MS PowerPoint and Impress. I was unable to work with the PowerPoint presentation using Impress.  The images, animations and text were all completely wrong when opened in Impress.

To be fair, I have created standalone presentations using Impress and the tool has a good feature set and works reliably.  I’ve used it to create and deliver presentations with no issues.  OpenOffice even seems to provide a nicer set of boilerplate presentation templates than the ones that come with MS PowerPoint.

My conclusion after working with OpenOffice now for about 3 months is that it is a completely viable solution if used as the document suite for a company. However, it is not possible to succeed with these tools in a heterogeneous environment where documents must be shared with MS Office users.

I will probably continue to use OpenOffice for personal work.  I’ll also continue to upgrade and try using it with MS Office documents from time to time.  Perhaps someday it will be possible to leverage this suite effectively in a multi-platform situation. Certainly from an ROI perspective it becomes harder and harder to justify the cost of the MS Office suite when such a capable and well-designed open source alternative exists.

Have you tried using alternatives to MS Office in a heterogeneous office tool environment?  Have you had better success than I have?  Any pointers on being able to succeed with such an approach?  Is such an approach even reasonable?  Please feel free to share your thoughts.

I was participating in a code review today and was reminded by a senior architect, who started working as an intern for me years ago, of a testing technique I had used with one of his first programs.  He had been assigned to create a basic web application that collected some data from a user and wrote it to a database.  He came into my office, announced it was done and proudly showed it to me.  I walked over to the keyboard, entered a bunch of junk and got a segmentation fault in response.

Although I didn’t have a name for it, that was a standard technique I used when evaluating applications.  After all, the tried and true paths, expected inputs and easy errors will be tested early and often as the developer exercises the application using the basic use cases.  As Boris Beizer said, “The high-probability paths are always tested if only to demonstrate that the system works properly.” (Beizer, Boris. Software Testing Techniques. Boston, MA: Thomson Computer Press, 1990: 76.)

It is unexpected input that is useful when looking to find untested paths through the code. If someone shows me an application for evaluation the last thing I need to worry about is using it in an expected fashion, everyone else will do that.  In fact, I default to entering data outside the specification when looking at a new application.  I don’t know that my team always appreciates the approach.  They’d probably like to see the application work at least once while I’m in the room.

These days there is a formal name for testing of this type, fuzzing.  A few years ago I preferred calling it “gorilla testing” since I liked the mental picture of beating on the application. (Remember the American Tourister luggage ad in the 1970s?)  But alas, it appears that fuzzing has become the accepted term.

Fuzzing involves passing input that breaks the expected input “rules”.  Those rules could come from some formal requirements, such as a RFC, or informal requirements, such as the set of parameters accepted by an application.  Fuzzing tools can use formal standards, extracted patterns and even randomly generated inputs to test an application’s resilience against unexpected or illegal input.

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The Internet is full of examples of simplifications creating vulnerabilities.  A good number of these can be represented as indirection enablers.  IP addresses, domain names, URIs, tiny URLs, QR Codes and now Microsoft tags.  Each of these serves the purpose of simplifying and decoupling.  We have seen many exploits for the first four, what about these last two?

As you likely know, QR Codes and Microsoft tags are graphical images targeted at print media, though there is no reason they can’t be used in an online fashion.  They are most often presented as rectangular graphics (examples below).  The reason for using them is to provide an easy way for someone to access a web page (or other online resource) related to the printed content.  Since these images represent character data they can also be used to house information, like contact details, that do not require online access to interpret.

The use case is simple: install a special program that interprets the codes or tags; point the camera from a smart phone or computer at the graphic; and voilà, your phone presents a web page, phone number or other embedded content. Basically this avoids having to manually enter a URL.  Depending on a company’s marketing strategy this is a powerful feature since a particular ad might want to direct a person to a URL that embeds  information about the specific advertisement, media source, publication page and so forth.  Typing in a complicated URL would put off many people but this removes most of the effort while making the print media interactive.

The main issues with adoption are educating the public about the use of these codes and getting people to install the reader software.  Some of you may recall Radio Shack trying to do something similar several years ago.  They created a scanning device, given out for free, that people had to connect to their PCs.  They could then scan a specific item in a Radio Shack catalog or advertisement and be brought to a web page with detailed information and ordering instructions.

Although that particular attempt failed, these newer approaches have the advantages of being broadly available, leveraging a common accessory on a smart phone (camera) and providing benefits to more than one company.  It will be interesting to see if any of the competing standards catch on with the general public (beyond the two mentioned already there are others such as Data Matrix, Quickmark and PDF417).

My concern, however, isn’t whether these graphical links become popular, it is whether they present another security risk. I believe that they do, in a manner similar to Tiny URLs, yet possibly more insidious.

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Being a consumer of semantic data I thought creating a SPARQL endpoint would be an interesting exercise.  It would require having some data to publish as well as working with a SPARQL library.  For data, I chose a set of mileage information that I have been collecting on my cars for the last 5 years.  For technology, I decided to use the Joseki SPARQL Server, since I was already using Jena.

For those who want to skip the “how” and see the result, the SPARQL endpoint along with sample queries and a link to the ontology and data is at: http://monead.com/semantic/query.html

The first step in this project was to convert my mileage spreadsheets into triples.  I looked briefly for an existing ontology in the automobile domain but didn’t find anything I could use.  I created an ontology that would reflect my approach to recording automobile mileage data.  My data  records the miles traveled between fill-ups as well as the number of gallons used.  I also record the car’s claimed MPG as well as calculating the actual MPG.

The ontology reflects this perspective of calculating the MPG at each fill-up.  This means that the purchase of gas is abstracted to a class with information such as miles traveled, gallons used and date of purchase as attributes.  I abstracted the gas station and location as classes, assuming that over time I might be able to flesh these out (in the spreadsheet I record the name of the station and the town/state).

A trivial Java program converts my spreadsheet (CSV) data into triples matching the ontology.  I then run the ontology and data through Pellet to derive any additional triples from the ontology.  The entire ontology and current data are available at http://monead.com/semantic/data/HybridMileageOntologyAll.Inferenced.xml.

It turns out that the ontology creation and data conversion were the easy parts of this project.  Getting Joseki to work as desired took some time, mostly because I couldn’t find much documentation for deploying it as a servlet rather than using its standalone server feature.  I eventually downloaded the Joseki source in order to understand what was going wrong.  The principle issue is that Joseki doesn’t seem to understand the WAR environment and relative paths (e.g. relative to its own WAR).

I had two major PATH issues: 1) getting Joseki to find its configuration (joseki-config.ttl); and 2) getting Joseki to find the triple store (in this case a flat file).

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I attended my first semantic web conference this week, the Semantic Web Summit (East) held in Boston.  The focus of the event was how businesses can leverage semantic technologies.  I was interested in what people were actually doing with the technology.  The one and a half days of presentations were informative and diverse.

Our host was Mills Davis, a name that I have encountered frequently during my exploration of the semantic web.  He did a great job of keeping the sessions running on time as well as engaging the audience.  The presentations were generally crisp and clear.  In some cases the speaker presented a product that utilizes semantic concepts, describing its role in the value chain.  In other cases we heard about challenges solved with semantic technologies.

My major takeaways were: 1) semantic technologies work and are being applied to a broad spectrum of problems and 2) the potential business applications of these technologies are vast and ripe for creative minds to explore.  This all bodes well for people delving into semantic technologies since there is an infrastructure of tools and techniques available upon which to build while permitting broad opportunities to benefit from leveraging them.

As a CTO with 20+ years focused on business environments, including application development, enterprise application integration, data warehousing, and business intelligence I identified most closely with the sessions geared around intra-business and B2B uses of semantic technology.  There were other sessions looking a B2C which were well done but not applicable to the world in which I find myself currently working.

Talks by Dennis Wisnosky and Mike Dunn were particularly focused on the business value that can be achieved through the use of semantic technologies.  Further, they helped to define basic best practices that they apply to such projects.  Dennis in particular gave specific information around his processes and architecture while talking about the enormous value that his team achieved.

Heartening to me was the fact that these best practices, processes and architectures are not significantly different than those used with other enterprise system endeavors.  So we don’t need to retool all our understanding of good project management practices and infrastructure design, we just need to internalize where semantic technology best fits into the technology stack.

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My last two days at JavaOne 2010 included some interesting sessions as well as spending some time in the pavilion.  I’ll mention a few of the session topics that I found interesting as well as some of the products that I intend to check out.

I attended a session on creating a web architecture focused on high-performance with low-bandwidth.  The speaker was tasked with designing a web-based framework for the government of Ethiopia.  He discussed the challenges that are presented by that country’s infrastructure – consider network speed on the order of 5Kbps between sites.  He also had to work with an IT group that, although educated and intelligent, did not have a lot of depth beyond working with an Oracle database’s features.

His solution allows developers to create fully functional web applications that keep exchanged payloads under 10K.  Although I understand the logic of the approach in this case, I’m not sure the technique would be practical in situations without such severe bandwidth and skill set limitations.

A basic theme during his talk was to keep the data and logic tightly co-located.  In his case it is all located in the database (PL/SQL) but he agreed that it could all be in the application tier (e.g. NoSQL).  I’m not convinced that this is a good approach to creating maintainable high-volume applications.  It could be that the domain of business applications and business verticals in which I often find myself differ from the use cases that are common to developers promoting the removal of tiers from the stack (whether removing the DB server or the mid-tier logic server).

One part of his approach with which I absolutely concur is to push processing onto the client. The use of the client’s CPU seems common sense to me.  The work is around balancing that with security and bandwidth.  However, it can be done and I believe we will continue to find more effective ways to leverage all that computer power.

I also enjoyed a presentation on moving data between a data center and the cloud to perform heavy and intermittent processing.  The presenters did a great job of describing their trials and successes with leveraging the cloud to perform computationally expensive processing on transient data (e.g. they copy the data up each time they run the process rather than pay to store their data).  They also provided a lot of interesting information regarding options, advantages and challenges when leveraging the cloud (Amazon EC2 in this case).

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I’ve been at Oracle’s combined JavaOne and OpenWorld events for two days.  I am here as both an attendee, learning from a variety of experts, and as a speaker.  Of course this is the first JavaOne since Oracle acquired Sun.  I have been to several JavaOne conferences over the years so I was curious how the event might be different.

One of the first changes that I’ve noticed is that due to the co-location of these two large conferences the venue is very different than when Sun ran JavaOne as a standalone event.  The time between sessions is a full half hour, probably due to the fact that you may find yourself going between venues that are several blocks apart.  I used to think that having getting from Moscone North the Moscone South took a while.   Now I’m walking from the Moscone center to a variety of hotels and back again.  Perhaps this is actually a health regime for programmers!

The new session pre-registration system is interesting. I don’t know if this system has been routine with Oracle’s other conferences but it is new to JavaOne.  Attendees go on-line and pre-register for the sessions they want to attend.  When you show up at the session your badge is scanned.  If you had registered you are allowed in.  If you didn’t preregister and the session is full you have to wait outside the room to see if anyone who registered fails to show up.

I think I like the system, with the assumption that they would stop people from entering when the room was full.  At previous conferences it seemed like popular sessions would just be standing room only, but that was probably a violation of fire codes.  The big advantage of this approach is that it reduces the likelihood of your investing the time to walk to the venue only to find out you can’t get in.  As long as you arranged your schedule on-line and you show up on-time, you’re guaranteed a seat.

Enough about new processes.  After all, I came here to co-present a session and to learn from a variety of others.

Paul Evans and I spoke on the topic of web services and their use with a rules engine. Specifically we were using JAX-WS and Drools.  We also threw in jUDDI to show the value of service location decoupling.  The session was well attended (essentially the room was full) and seemed to keep the attendees’ attention.  We had some good follow-up conversations regarding aspects of the presentation that caught people’s interest, which is always rewarding. The source code for the demonstration program is located at http://bit.ly/blueslate-javaone2010.

Since I am a speaker I have access to both JavaOne and OpenWorld sessions.  I took advantage of that by attending several OpenWorld sessions in addition to a bunch of JavaOne talks.

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I received a helpful push from Paul Evans this evening.  He reminded me that the Semantic Workbench SourceForge project (semanticwb.sourceforge.net) is just sitting idle, waiting to be kicked-off.  We talked about the vision around the project, which needs to be clearly and concisely articulated as a mission.  At that point we’ll have a direction to take.

This conversation coincided with my attendance at two semantic-web presentations at Oracle OpenWorld, which I am able to attend since it is co-located with JavaOne.  I’ll write more about my experiences at this year’s JavaOne conference soon.

These semantic -web presentations validated the value of semantic technologies and the need to make them more visible to the IT community.  For my part, this means I need to do more writing and presenting about semantic technologies while creating a renewed vigor around the Semantic Workbench project.

As Paul and I spoke and I tried to define my vision around the project, I realized that I was being too wordy for a mission statement.  The fundamentals of my depiction were also different from the current project overview on SourceForge.  The overview does not describe the truly useful application that I would like to see come out of the project.

Recognizing this disconnect reinforced the need to come up with a more useful and actionable mission.  In the hopes that the project can be of value, I present this mission statement:

The Semantic Workbench strives to provide a complete Java-based GUI and tool set for exploring, testing, and validating common semantic web-based operations.

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