Welcome!

Java IoT Authors: Elizabeth White, Pat Romanski, Liz McMillan, Flint Brenton, Harry Trott

Related Topics: Java IoT, Industrial IoT

Java IoT: Article

How OpenKM's Technical Debt Decreased by 49% Through Code Refactoring

Initial Technical Debt of the project reduced from 84 to 42 days of remediation

Technical Debt is worth nothing if no pragmatic action is taken into code, in order to control and tackle it. To ilustrate the Scertify's capability to automatically correct code defects that increase this unintended debt, we performed code refactoring on OpenKM, an Free/Libre document management system. The initial Technical Debt of the project has been reduced by 49.2% from 84 days to 42 days. Here, at Tocea, we call it the Debt Write-Off.

For this first Debt Write-Off, we have decided to perform the refactoring of OpenKM (6.2.1-DEV).

According to Wikipedia, OpenKM is a Free/Libre document management system that provides a web interface for managing arbitrary files. OpenKM is a great tool but an audit of the code revealed some technical debt problems. That was a good opportunity to use Scertify and to be useful to an open-source community. The application consists mainly in 200K lines of code of Java. There is also Javascript, JSP, CSS... but we focus here on the Java code.

Technical debt before refactoring

Scertify Refactoring Assessment allows us to estimate the technical debt of the application. As you can see on screenshot #1, it is estimated to 84 days. This is the time needed to correct manually each error. This number only includes the time needed to make the change on the code, it does not include things like finding the file, understanding the problem, etc.

Of this 84 days, 60 represent errors that can be automatically refactored, thus taking nearly zero effort to correct.

We can take a closer look on the possibilities of automation (screenshot #2). Not all rules are currently implemented in Scertify, but we are working on it. For this project, we chose 7 rules that seemed particularly interesting.

Rules used for the refactoring

Here's a presentation of the rules used to perform the refactoring of OpenKM.

  • AvoidPrintStackTrace

    This rule reports a violation when it finds a code that catch an expression and print its stack trace to the standard error output. A logging framework should be used instead, in order to improve application's maintainability.
    The refactoring replace a call to print stack trace by a call to a logging framework. The rule can also declare the logger in the class and make the required imports. The rule can be configured to use the user's favorite framework.

    Here's the configuration used for OpenKM:

    • The logger call to use: "log.error({0}.getMessage(), {0})" {0} is replaced by the exception.
    • Do not refactor calls of printStackTrace to other IO (a file, a stream...)
    • Make logger declaration when it's needed (ie: log is not already declared in class).
    • The logger declaration to use : "private static Logger log = LoggerFactory.getLogger({0}.class);"
    • The required imports : "org.slf4j.LoggerFactory,org.slf4j.Logger"

    Original code :

    view source print? 1.catch(FileNotFoundExceptione){ e.printStackTrace(); }
  • Refactored code :

    view source print? 1.catch(FileNotFoundExceptione){ log.error(e.getMessage(),e); }
  • AddEmptyStringToConvert

    Using the concatenation of an empty string to convert a primitive type to a String is a bad practice. First of all, it makes the code less readable. It is also less efficient in most cases (the only case where the string concatenation is slightly better is when the primitive is final).

    Original code:

    view source print? 1.UserActivity.log(session.getUserID(), "DELETE_PROCESS_DEFINITION",""+processDefinitionId, null,null);

    Refactored code:

    view source print? 1.UserActivity.log(session.getUserID(), "DELETE_PROCESS_DEFINITION", String.valueOf(processDefinitionId),null,null);
  • InefficientConstructorCall

    Calling the constructor of a wrapper type, like Integer, to convert a primitive type is a bad practice. It is less efficient than calling the static method valueOf.

    Original code:

    view source print? 1.users.put(usersRead[i].getString(), newInteger(Permission.READ));

    Refactored code:

    view source print? 1.users.put(usersRead[i].getString(), newInteger(Permission.READ));
  • IfElseStmtsMustUseBraces

    This rule finds if statements that don't use braces. The refactoring adds required braces.

  • PositionLiteralsFirstInComparisonsRefactor

    This rule checks that literals are in the first position in comparisons. The following code is a violation :

    Original code:

    view source print? 1.if(action.equals("ruleList"))

    Refactored code:

    view source print? 1.if("ruleList".equals(action))

    The refactoring invert the literal and the variable. This ensures that the code cannot crash due to the variable being a null pointer.

  • MethodArgumentCouldBeFinal

    This method flags method's arguments that could be declared final and are not. The use of the final keyword is a useful information for future code readers.

  • LocalVariableCouldBeFinal

    The purpose is the same as the previous rule, except that it treats local variable and not arguments. These two rules are not critical, but since they have a huge number of violations, it is useful to get rid of them quickly with automatic refactoring.

We are now ready to perform the refactoring with Scertify.

    The refactoring process

    The refactoring process consists of two steps :

  1. Configure a xml rule repository: The first step is crucial. As we have seen in previous section, some rules need to be configured to be useful. However, it shouldn't take more than half an hour.
  2. Run Scertify to perform the refactoring: The second step is just a command line invocation, where you specify the project to refactor and the rule repository to use.

For this project of 200K lines of code, the refactoring took 2 minute. You can check the process on a smaller project in this video tutorial.

Technical debt after refactoring
Screenshot #3 is the analysis of the refactored project by Scertify Refactoring Assessment. As you can see, 24 days of technical debt have been erased.

Screenshot #4 and #5 show the difference of violations in Sonar between the original and the refactored project.

Here's the number of violations that have been corrected for each rule (*) :

  • AddEmptyStringToConvert: 232
  • AvoidPrintStackTrace: 70
  • InefficientConstructorCall: 43
  • IFElseStmtsMustUseBraces: 411
  • PositionLiteralsFirstInComparisons: 358
  • MethodArgumentCouldBeFinal: 8848
  • LocalVariableCouldBeFinal : 7622

To sum up, with Scertify we've been able to correct quickly a huge number of errors. Some of them are not critical (like MethodArgumentCouldBeFinal) but we've also been able to refactor more evolved errors like AvoidPrintStackTrace, AddEmptyStringToConvert,...

Download the source files

(*) if you do the math, you'll see that more errors have been corrected. It's due to side effects of the refactoring (correcting a rule can remove violations of other rules) and also because we manually corrected few things in the code.

Submit your project for a Debt Write-Off

If you're interested in submitting your project to the next Debt Write-off, or just give some valuable feedback... Please contact us on Twitter: @Scertify

More Stories By Michael Muller

Michael Muller, a Marketing Manager at Tocea, has 10+ years of experience as a Marketing and Communication Manager. He specializes in technology and innovative companies. He is executive editor at http://dsisionnel.com, a French IT magazine and the creator of http://d8p.it, a cool URL shortener. Dad of two kids.

@ThingsExpo Stories
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...
IoT offers a value of almost $4 trillion to the manufacturing industry through platforms that can improve margins, optimize operations & drive high performance work teams. By using IoT technologies as a foundation, manufacturing customers are integrating worker safety with manufacturing systems, driving deep collaboration and utilizing analytics to exponentially increased per-unit margins. However, as Benoit Lheureux, the VP for Research at Gartner points out, “IoT project implementers often ...
Basho Technologies has announced the latest release of Basho Riak TS, version 1.3. Riak TS is an enterprise-grade NoSQL database optimized for Internet of Things (IoT). The open source version enables developers to download the software for free and use it in production as well as make contributions to the code and develop applications around Riak TS. Enhancements to Riak TS make it quick, easy and cost-effective to spin up an instance to test new ideas and build IoT applications. In addition to...
Presidio has received the 2015 EMC Partner Services Quality Award from EMC Corporation for achieving outstanding service excellence and customer satisfaction as measured by the EMC Partner Services Quality (PSQ) program. Presidio was also honored as the 2015 EMC Americas Marketing Excellence Partner of the Year and 2015 Mid-Market East Partner of the Year. The EMC PSQ program is a project-specific survey program designed for partners with Service Partner designations to solicit customer feedbac...
In his general session at 18th Cloud Expo, Lee Atchison, Principal Cloud Architect and Advocate at New Relic, discussed cloud as a ‘better data center’ and how it adds new capacity (faster) and improves application availability (redundancy). The cloud is a ‘Dynamic Tool for Dynamic Apps’ and resource allocation is an integral part of your application architecture, so use only the resources you need and allocate /de-allocate resources on the fly.
Machine Learning helps make complex systems more efficient. By applying advanced Machine Learning techniques such as Cognitive Fingerprinting, wind project operators can utilize these tools to learn from collected data, detect regular patterns, and optimize their own operations. In his session at 18th Cloud Expo, Stuart Gillen, Director of Business Development at SparkCognition, discussed how research has demonstrated the value of Machine Learning in delivering next generation analytics to imp...
It is one thing to build single industrial IoT applications, but what will it take to build the Smart Cities and truly society changing applications of the future? The technology won’t be the problem, it will be the number of parties that need to work together and be aligned in their motivation to succeed. In his Day 2 Keynote at @ThingsExpo, Henrik Kenani Dahlgren, Portfolio Marketing Manager at Ericsson, discussed how to plan to cooperate, partner, and form lasting all-star teams to change t...
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life sett...
There are several IoTs: the Industrial Internet, Consumer Wearables, Wearables and Healthcare, Supply Chains, and the movement toward Smart Grids, Cities, Regions, and Nations. There are competing communications standards every step of the way, a bewildering array of sensors and devices, and an entire world of competing data analytics platforms. To some this appears to be chaos. In this power panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, Bradley Holt, Developer Advocate a...
Connected devices and the industrial internet are growing exponentially every year with Cisco expecting 50 billion devices to be in operation by 2020. In this period of growth, location-based insights are becoming invaluable to many businesses as they adopt new connected technologies. Knowing when and where these devices connect from is critical for a number of scenarios in supply chain management, disaster management, emergency response, M2M, location marketing and more. In his session at @Th...
The cloud market growth today is largely in public clouds. While there is a lot of spend in IT departments in virtualization, these aren’t yet translating into a true “cloud” experience within the enterprise. What is stopping the growth of the “private cloud” market? In his general session at 18th Cloud Expo, Nara Rajagopalan, CEO of Accelerite, explored the challenges in deploying, managing, and getting adoption for a private cloud within an enterprise. What are the key differences between wh...
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, wh...
Cloud computing is being adopted in one form or another by 94% of enterprises today. Tens of billions of new devices are being connected to The Internet of Things. And Big Data is driving this bus. An exponential increase is expected in the amount of information being processed, managed, analyzed, and acted upon by enterprise IT. This amazing is not part of some distant future - it is happening today. One report shows a 650% increase in enterprise data by 2020. Other estimates are even higher....
SYS-CON Events announced today that Bsquare has been named “Silver Sponsor” of SYS-CON's @ThingsExpo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. For more than two decades, Bsquare has helped its customers extract business value from a broad array of physical assets by making them intelligent, connecting them, and using the data they generate to optimize business processes.
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices - comp...
19th Cloud Expo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Meanwhile, 94% of enterpri...
The 19th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Digital Transformation, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportuni...
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 19th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world and ThingsExpo Silicon Valley Call for Papers is now open.
There is little doubt that Big Data solutions will have an increasing role in the Enterprise IT mainstream over time. Big Data at Cloud Expo - to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA - has announced its Call for Papers is open. Cloud computing is being adopted in one form or another by 94% of enterprises today. Tens of billions of new devices are being connected to The Internet of Things. And Big Data is driving this bus. An exponential increase is...
Cognitive Computing is becoming the foundation for a new generation of solutions that have the potential to transform business. Unlike traditional approaches to building solutions, a cognitive computing approach allows the data to help determine the way applications are designed. This contrasts with conventional software development that begins with defining logic based on the current way a business operates. In her session at 18th Cloud Expo, Judith S. Hurwitz, President and CEO of Hurwitz & ...