Struts 2 – Development mode example

In Struts 2 development, this should be the first configurable value to learn. To enable the Struts 2 development mode, you can significantly increase your Struts 2 development speed by giving auto configuration and properties files reload and extra logging and debugging feature.

The auto reload feature is really a convenient feature. Each time i made changed in properties or XML configuration file, the application is no longer need to restart to take effect.
By default, the Struts 2 development mode is disabled.

Enable the Strut2 development mode

Set the “struts.devMode” value to true, either in Struts properties file or XML configuration file.

struts.devMode = true


 	<constant name="struts.devMode" value="true" />	

Disable the Strut2 development mode

Set the “struts.devMode” to false, either in Struts properties file or XML configuration file.

struts.devMode = false


 	<constant name="struts.devMode" value="false" />	
The development mode is only suitable in development or debugging environment. In production environment, you HAVE TO disabled it. It will caused significant impact on performance, because the entire application configuration, properties files will be reloaded on every request, many extra logging and debug information will be provide also.
Before commit Struts configuration file, just make sure the development mode is turn off. I saw many accidentally commit cases – commit with development mode enable, and someone just grab the source code for QA environment. To be Frankly, QA seldom will do the performance test, they just make sure the functionality are there, and end with a development mode enabled application deployed to the production. Guess what? you will receive many screaming phone calls from clients very soon…


  1. Struts 2 development mode documentation
Tags :

About the Author

Founder of and, love Java and open source stuff. Follow him on Twitter, or befriend him on Facebook or Google Plus. If you like my tutorials, consider make a donation to these charities.


  • Pingback: over here()

  • Pingback: this post()

  • Pingback: water ionizer()

  • Pingback: water ionizer payment plan()

  • Pingback: house blue()

  • Pingback: zak?ad szklarski piotrk√≥w trybunalski()

  • Pingback: pay per day loans plan()

  • Pingback: list of plumbers tools()

  • Pingback: plumbing jobs available perth wa()

  • Pingback: locksmith zachary()

  • Pingback: pop over to this site()

  • Pingback: electrician a hard job()

  • Pingback: one-time offer()

  • Pingback: alkaline water brands()

  • Pingback: pay day loans()

  • Pingback: water ionizer()

  • Pingback: stop parking()

  • Pingback: alkaline water machine()

  • Pingback: laan hurtige penge nu()

  • Pingback: mp4 mobile porn()

  • Pingback: car parking()

  • Pingback: here()

  • Pingback: best online casinos()

  • Pingback: How to unblock Viber in UAE()

  • Pingback: kangen()

  • Pingback: kangen water()

  • Pingback: alkaline water()

  • Pingback: water ionizer()

  • Pingback: tv online, online tv()

  • Pingback: free movie downloads()

  • Pingback: Blue Coaster33()

  • vikas

    But sir what is main need of this devMode true/false?

    There is no effect in my application while changing it either T/F.

  • Chandu

    Hi Yong,

    We are also facing same problem as Hariprasad said in previous post.

    We are using jar like struts2-core-2.3.1.jar , struts2-dojo-plugin-2.3.1.jar ..etc

    We are using struts xml type validations.

    In jsp(myDataList.jsp) our code as below:

    .. ..

    struts.xml configuration:
    .. ..


    Error we are getting as below:

    Caused by: javax.servlet.ServletException: javax.servlet.jsp.JspException: IO Error executing tag: JSPException including path ‘/jsp/vesselPerformance/noonReportList.jsp’.
    at org.apache.jasper.runtime.PageContextImpl.doHandlePageException( [:6.1.0.Final]

    … 73 more
    Caused by: org.apache.tiles.util.TilesIOException: JSPException including path ‘/jsp/vesselPerformance/noonReportList.jsp’.
    at org.apache.tiles.servlet.context.ServletTilesRequestContext.wrapServletException( [:2.0.6]
    … 86 more
    Caused by: tag ‘select’, field ‘list’, name ‘vesselPerformanceRequestDTO.operatorId': The requested list key ‘operators’ could not be resolved as a collection/array/map/enumeration/iterator type. Example: people or people.{name} – [unknown location]
    at org.apache.struts2.components.Component.fieldError( [:2.3.1]

    Previously it working fine with the “struts.devMode=true” but recently we changed to struts.devMode=false to optimize the performance. Validations are not working with this.

    Thanks in advance.

    – Chandu

  • Hariprasad

    I have put in strut.xml file but my application vaildation is not working and when i see vew source there is no validation for the fields but when put struts.devMode=true javascript validation is displaying for the fields and when i click on save or submit button displaying error in console
    tag ‘select’, field ‘list’, name ‘userListDTO.appUserAccount.roleName': The requested list key ‘roles’ could not be resolved as a collection/array/map/enumeration/iterator type. Example: people or people.{name} – [unknown location]

    please suggest us .




  • Active

    This is the best website I have visited. Very good explanation of every article. The best part is they have included even very small topics , which you will rarely find on any site. It makes the development very easy.

    • mkyong

      Thanks, good to know it help you in some ways.

      • phoudthavong

        it was great. you help me a lot. I am so appreciated.

  • Ash

    Mr Yong,
    Toooo Gooood Article
    The website is Simply Best!!! Absolutely loved it