Click here to close now.

Welcome!

Java Authors: AppDynamics Blog, Kelly Murphy, John Smith, Pat Romanski, 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
Wearable devices have come of age. The primary applications of wearables so far have been "the Quantified Self" or the tracking of one's fitness and health status. We propose the evolution of wearables into social and emotional communication devices. Our BE(tm) sensor uses light to visualize the skin conductance response. Our sensors are very inexpensive and can be massively distributed to audiences or groups of any size, in order to gauge reactions to performances, video, or any kind of presentation. In her session at @ThingsExpo, Jocelyn Scheirer, CEO & Founder of Bionolux, will discuss ho...
The true value of the Internet of Things (IoT) lies not just in the data, but through the services that protect the data, perform the analysis and present findings in a usable way. With many IoT elements rooted in traditional IT components, Big Data and IoT isn’t just a play for enterprise. In fact, the IoT presents SMBs with the prospect of launching entirely new activities and exploring innovative areas. CompTIA research identifies several areas where IoT is expected to have the greatest impact.
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.
Every day we read jaw-dropping stats on the explosion of data. We allocate significant resources to harness and better understand it. We build businesses around it. But we’ve only just begun. For big payoffs in Big Data, CIOs are turning to cognitive computing. Cognitive computing’s ability to securely extract insights, understand natural language, and get smarter each time it’s used is the next, logical step for Big Data.
There's no doubt that the Internet of Things is driving the next wave of innovation. Google has spent billions over the past few months vacuuming up companies that specialize in smart appliances and machine learning. Already, Philips light bulbs, Audi automobiles, and Samsung washers and dryers can communicate with and be controlled from mobile devices. To take advantage of the opportunities the Internet of Things brings to your business, you'll want to start preparing now.
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.
P2P RTC will impact the landscape of communications, shifting from traditional telephony style communications models to OTT (Over-The-Top) cloud assisted & PaaS (Platform as a Service) communication services. The P2P shift will impact many areas of our lives, from mobile communication, human interactive web services, RTC and telephony infrastructure, user federation, security and privacy implications, business costs, and scalability. In his session at @ThingsExpo, Robin Raymond, Chief Architect at Hookflash, will walk through the shifting landscape of traditional telephone and voice services ...
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at Internet of @ThingsExpo, James Kirkland, Chief Architect for the Internet of Things and Intelligent Systems at Red Hat, described how to revolutioniz...
For IoT to grow as quickly as analyst firms’ project, a lot is going to fall on developers to quickly bring applications to market. But the lack of a standard development platform threatens to slow growth and make application development more time consuming and costly, much like we’ve seen in the mobile space. In his session at @ThingsExpo, Mike Weiner is Product Manager of the Omega DevCloud with KORE Telematics Inc., will discuss the evolving requirements for developers as IoT matures and conduct a live demonstration of how quickly application development can happen when the need to comply...
SYS-CON Events announced today that DragonGlass, an enterprise search platform, will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. After eleven years of designing and building custom applications, OpenCrowd has launched DragonGlass, a cloud-based platform that enables the development of search-based applications. These are a new breed of applications that utilize a search index as their backbone for data retrieval. They can easily adapt to new data sets and provide access to both structured and unstruc...
Converging digital disruptions is creating a major sea change - Cisco calls this the Internet of Everything (IoE). IoE is the network connection of People, Process, Data and Things, fueled by Cloud, Mobile, Social, Analytics and Security, and it represents a $19Trillion value-at-stake over the next 10 years. In her keynote at @ThingsExpo, Manjula Talreja, VP of Cisco Consulting Services, will discuss IoE and the enormous opportunities it provides to public and private firms alike. She will share what businesses must do to thrive in the IoE economy, citing examples from several industry sector...
Container frameworks, such as Docker, provide a variety of benefits, including density of deployment across infrastructure, convenience for application developers to push updates with low operational hand-holding, and a fairly well-defined deployment workflow that can be orchestrated. Container frameworks also enable a DevOps approach to application development by cleanly separating concerns between operations and development teams. But running multi-container, multi-server apps with containers is very hard. You have to learn five new and different technologies and best practices (libswarm, sy...
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...
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.
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 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.