Click here to close now.

Welcome!

Java Authors: Elizabeth White, Wayne Lam, William Schmarzo, Liz McMillan, Carmen Gonzalez

Related Topics: Java, XML

Java: 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
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo in Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th 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 an...
The security devil is always in the details of the attack: the ones you've endured, the ones you prepare yourself to fend off, and the ones that, you fear, will catch you completely unaware and defenseless. The Internet of Things (IoT) is nothing if not an endless proliferation of details. It's the vision of a world in which continuous Internet connectivity and addressability is embedded into a growing range of human artifacts, into the natural world, and even into our smartphones, appliances, and physical persons. In the IoT vision, every new "thing" - sensor, actuator, data source, data con...
Buzzword alert: Microservices and IoT at a DevOps conference? What could possibly go wrong? In this Power Panel at DevOps Summit, moderated by Jason Bloomberg, the leading expert on architecting agility for the enterprise and president of Intellyx, panelists will peel away the buzz and discuss the important architectural principles behind implementing IoT solutions for the enterprise. As remote IoT devices and sensors become increasingly intelligent, they become part of our distributed cloud environment, and we must architect and code accordingly. At the very least, you'll have no problem fil...
IoT is still a vague buzzword for many people. In his session at @ThingsExpo, Mike Kavis, Vice President & Principal Cloud Architect at Cloud Technology Partners, discussed the business value of IoT that goes far beyond the general public's perception that IoT is all about wearables and home consumer services. He also discussed how IoT is perceived by investors and how venture capitalist access this space. Other topics discussed were barriers to success, what is new, what is old, and what the future may hold. Mike Kavis is Vice President & Principal Cloud Architect at Cloud Technology Pa...
Disruptive macro trends in technology are impacting and dramatically changing the "art of the possible" relative to supply chain management practices through the innovative use of IoT, cloud, machine learning and Big Data to enable connected ecosystems of engagement. Enterprise informatics can now move beyond point solutions that merely monitor the past and implement integrated enterprise fabrics that enable end-to-end supply chain visibility to improve customer service delivery and optimize supplier management. Learn about enterprise architecture strategies for designing connected systems tha...
There's Big Data, then there's really Big Data from the Internet of Things. IoT is evolving to include many data possibilities like new types of event, log and network data. The volumes are enormous, generating tens of billions of logs per day, which raise data challenges. Early IoT deployments are relying heavily on both the cloud and managed service providers to navigate these challenges. In her session at Big Data Expo®, Hannah Smalltree, Director at Treasure Data, discussed how IoT, Big Data and deployments are processing massive data volumes from wearables, utilities and other machines...
SYS-CON Events announced today that the "First Containers & Microservices Conference" will take place June 9-11, 2015, at the Javits Center in New York City. The “Second Containers & Microservices Conference” will take place November 3-5, 2015, at Santa Clara Convention Center, Santa Clara, CA. Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities.
SYS-CON Events announced today that MetraTech, now part of Ericsson, has been named “Silver Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9–11, 2015, at the Javits Center in New York, NY. Ericsson is the driving force behind the Networked Society- a world leader in communications infrastructure, software and services. Some 40% of the world’s mobile traffic runs through networks Ericsson has supplied, serving more than 2.5 billion subscribers.
The 4th International Internet of @ThingsExpo, co-located with the 17th International Cloud Expo - to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA - announces that its Call for Papers is open. The Internet of Things (IoT) is the biggest idea since the creation of the Worldwide Web more than 20 years ago.
The 17th International Cloud Expo has announced that its Call for Papers is open. 17th International Cloud Expo, to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, APM, APIs, Microservices, Security, Big Data, Internet of Things, DevOps 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 opportunity. Submit your speaking proposal today!
Since 2008 and for the first time in history, more than half of humans live in urban areas, urging cities to become “smart.” Today, cities can leverage the wide availability of smartphones combined with new technologies such as Beacons or NFC to connect their urban furniture and environment to create citizen-first services that improve transportation, way-finding and information delivery. In her session at @ThingsExpo, Laetitia Gazel-Anthoine, CEO of Connecthings, will focus on successful use cases.
The explosion of connected devices / sensors is creating an ever-expanding set of new and valuable data. In parallel the emerging capability of Big Data technologies to store, access, analyze, and react to this data is producing changes in business models under the umbrella of the Internet of Things (IoT). In particular within the Insurance industry, IoT appears positioned to enable deep changes by altering relationships between insurers, distributors, and the insured. In his session at @ThingsExpo, Michael Sick, a Senior Manager and Big Data Architect within Ernst and Young's Financial Servi...
The recent trends like cloud computing, social, mobile and Internet of Things are forcing enterprises to modernize in order to compete in the competitive globalized markets. However, enterprises are approaching newer technologies with a more silo-ed way, gaining only sub optimal benefits. The Modern Enterprise model is presented as a newer way to think of enterprise IT, which takes a more holistic approach to embracing modern technologies.
17th Cloud Expo, taking place Nov 3-5, 2015, 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 enterprises are using some form of XaaS – software, platform, and infrastructure as a service.
One of the biggest impacts of the Internet of Things is and will continue to be on data; specifically data volume, management and usage. Companies are scrambling to adapt to this new and unpredictable data reality with legacy infrastructure that cannot handle the speed and volume of data. In his session at @ThingsExpo, Don DeLoach, CEO and president of Infobright, will discuss how companies need to rethink their data infrastructure to participate in the IoT, including: Data storage: Understanding the kinds of data: structured, unstructured, big/small? Analytics: What kinds and how responsiv...
The Workspace-as-a-Service (WaaS) market will grow to $6.4B by 2018. In his session at 16th Cloud Expo, Seth Bostock, CEO of IndependenceIT, will begin by walking the audience through the evolution of Workspace as-a-Service, where it is now vs. where it going. To look beyond the desktop we must understand exactly what WaaS is, who the users are, and where it is going in the future. IT departments, ISVs and service providers must look to workflow and automation capabilities to adapt to growing demand and the rapidly changing workspace model.
From telemedicine to smart cars, digital homes and industrial monitoring, the explosive growth of IoT has created exciting new business opportunities for real time calls and messaging. In his session at @ThingsExpo, Ivelin Ivanov, CEO and Co-Founder of Telestax, shared some of the new revenue sources that IoT created for Restcomm – the open source telephony platform from Telestax. Ivelin Ivanov is a technology entrepreneur who founded Mobicents, an Open Source VoIP Platform, to help create, deploy, and manage applications integrating voice, video and data. He is the co-founder of TeleStax, a...
The Internet of Things (IoT) promises to evolve the way the world does business; however, understanding how to apply it to your company can be a mystery. Most people struggle with understanding the potential business uses or tend to get caught up in the technology, resulting in solutions that fail to meet even minimum business goals. In his session at @ThingsExpo, Jesse Shiah, CEO / President / Co-Founder of AgilePoint Inc., showed what is needed to leverage the IoT to transform your business. He discussed opportunities and challenges ahead for the IoT from a market and technical point of vie...
Sensor-enabled things are becoming more commonplace, precursors to a larger and more complex framework that most consider the ultimate promise of the IoT: things connecting, interacting, sharing, storing, and over time perhaps learning and predicting based on habits, behaviors, location, preferences, purchases and more. In his session at @ThingsExpo, Tom Wesselman, Director of Communications Ecosystem Architecture at Plantronics, will examine the still nascent IoT as it is coalescing, including what it is today, what it might ultimately be, the role of wearable tech, and technology gaps stil...
DevOps tends to focus on the relationship between Dev and Ops, putting an emphasis on the ops and application infrastructure. But that’s changing with microservices architectures. In her session at DevOps Summit, Lori MacVittie, Evangelist for F5 Networks, will focus on how microservices are changing the underlying architectures needed to scale, secure and deliver applications based on highly distributed (micro) services and why that means an expansion into “the network” for DevOps.