Setting Web Container Custom properties

The WebSphere Application Server allows you to configure behavior of the Web Container at system level by setting some predefined custom properties.

You can set custom Web Container properties using WAS Admin Console, by going to Application servers > servername > Web container > Custom Properties. This is screen shot of custom properties that are set on my local WebSphere Portal Installation



These are list of properties and their meanings in WAS 6.1

1. com.ibm.ws.webcontainer.disallowserveservletsbyclassname: When the serveServletsByClassnameEnabled property is enabled, it is possible to access servlets directly, resulting in a possible security exposure. Define the following custom property to disallow the use of the serveServletsByClassnameEnabled property across the entire application server level.


2. com.ibm.ws.webcontainer.donotservebyclassname: A semi-colon delimited list of classes to be completely disallowed from being served by class name.


3. com.ibm.ws.webcontainer.suppressheadersinrequest: The com.ibm.ws.webcontainer.suppressheadersinrequest custom property can be used to suppress the inclusion of request headers that start with special characters, such as "$" or "_" . Some applications do not handle request headers that start with special characters


4. com.ibm.ws.webcontainer.webgroupvhostnotfound: Error message SRVE0017W states "Web Group not found: {0}", and error message SRVE0255 states "A WebGroup/Virtual Host to handle {0} has not been defined". These messages might be returned when the application that is called to process the request serviced by IBM WebSphere Application Server is not found. You can use the com.ibm.ws.webcontainer.webgroupvhostnotfound custom property to change the text of these message to text that is more suitable for your environment.


5. DecodeUrlAsUTF8: The UTF-8 encoded URL feature, which provides UTF-8 encoded Uniform Resource Locators (URLs) to support the double-byte characters in URLs is enabled by default. You can prevent the Web container from explicitly decoding URLs in UTF-8 and have them use the ISO-8859 standard as per the current HTTP specification by setting value of DecodeUrlAsUTF8 to false


6. listeners: The servlet specification supports applications registering listeners for servlet-related events on an individual application basis through the web.xml descriptor. However, using the listeners custom property, a server can listen to servlet events across Web applications. To implement global listening, a listener is registered at the Web container level and is propagated to all of the installed and new Web applications. You can create a Servlet Listener following the J2EE specification and specify its name here to apply it to all the web applications


7. DebugSessionCrossover:The DebugSessionCrossover custom property enables code to perform additional checks to verify that only the session associated with the request is accessed or referenced. Messages are logged if any discrepancies are detected.


8. com.ibm.wsspi.jsp.disableTldSearch: The com.ibm.wsspi.jsp.disableTldSearch custom property can be used to improve application startup time. By default, when an application starts, the JSP engine searches the application installation directories for the taglib descriptor (TLD) files. This search process might increase the startup time for large applications with a large number of files and directories. To disable this search process, set the value of this property to true


9. com.ibm.ws.webcontainer.disallowAllFileServing:You can enable file serving on a global level across a given application server by using the fileServingEnabled custom property. However, the fileServingEnabled property is overridden by the specific deployment information of each application. Therefore,, the current fileServingEnabled custom property only applies as a backup in case an application does not define the fileServingEnabled setting itself. To globally override this setting on a specific application server to prevent the application server from serving static files regardless of their individual deployment settings, set the Web container custom property com.ibm.ws.webcontainer.disallowAllFileServing to true.


10. com.ibm.ws.webcontainer.mapFiltersToAsterisk:When processing a request, the Web container recognizes servlet mappings to "*" as the same as servlet mappings to "/*". To provide the same behavior with filter mapping, set the com.ibm.ws.webcontainer.mapFiltersToAsterisk custom property to true. Setting the com.ibm.ws.webcontainer.mapFiltersToAsterisk custom property to true causes the Web container to recognize filter mappings to "*" as a filter mapping to "/*" . This custom property is not case sensitive.