Change or adding WAR files

 

You can change Web application archives (WAR files) on appservers without having to stop the server and start it again.

 

Overview

There are several changes that you can make to WAR files without stopping the server and starting it again.

See Ways to update application files and determine whether hot deployment is the appropriate way for you to update your WAR files. Other ways are easier and hot deployment is appropriate only for experienced users. You can use the update wizard of the console to make the changes without having to stop and restart the server.

The following table lists the changes that you can make by manipulating a WAR file on the server where the application is deployed. The table also states whether you use hot deployment or dynamic reloading to make the changes.

Change	Hot deployment	Dynamic reloading
Change an existing JavaServer Pages file.	Not applicable	Yes
Add a new JSP file to an existing application.	Yes	Yes
Change an existing servlet class by editing and recompiling.	Not applicable	Yes
Change a dependent class of an existing servlet class.	Not applicable	Yes
Add a new servlet using the Invoker (Serve Servlets by class name) facility or add a dependent class to an existing application.	Yes	Not applicable
Add a new servlet, including a new definition of the servlet in the web.xml deployment descriptor for the application.	Yes	Not applicable
Change the web.xml file of a WAR file.	Yes	Yes
Change the ibm-web-ext.xmi file of a WAR file.	Not applicable	Yes
Change the ibm-web-bnd.xmi file of a WAR file.	Not applicable	Yes

 

Procedure

• Change an existing JavaServer Pages file.

  Place the changed JSP file directly in the application_root/module_name directory or the appropriate subdirectory. The change will be automatically detected and the JSP will be recompiled and reloaded.

• Add a new JSP file to an existing application.

  Place the new JSP file directly in the application_root/module_name directory or the appropriate subdirectory. The new file will be automatically detected and compiled on the first request to the page.

• Change an existing servlet class by editing and recompiling.

  1. Place the new version of the servlet .class file directly in the application_root/module_name/WEB-INF/classes directory. If the .class file is part of a Jar file, you can place the new version of the Jar file directly in application_root/module_name/WEB-INF/lib. In either case, the change will be detected, the Web application will be shut down and reinitialized, picking up the new class.

  2. If automatic reloading is not enabled, restart the application. Use the console to restart the application. Or run the wasadmin stopApplication and startApplication commands.

     If automatic reloading is enabled, you do not need to take further action. Automatic reloading will detect the change.

• Change a dependent class of an existing servlet class.

  1. Place the new version of the dependent .class file directly in the application_root/module_name/WEB-INF/classes directory. If the .class file is part of a Jar file, you can place the new version of the Jar file directly in application_root/module_name/WEB-INF/lib. In either case, the change will be detected, the Web application will be shut down and reinitialized, picking up the new class.

  2. If automatic reloading is not enabled, restart the application. Use the console to restart the application. Or run the wasadmin stopApplication and startApplication commands.

     If automatic reloading is enabled, you do not need to take further action. Automatic reloading will detect the change.

• Add a new servlet using the Invoker (Serve Servlets by class name) facility or add a dependent class to an existing application.

  1. Place the new .class file directly in the application_root/module_name/WEB-INF/classes directory. If the .class file is part of a Jar file, you can place the new version of the Jar file directly in application_root/module_name/WEB-INF/lib. In either case, the change will be detected, the Web application will be shut down and reinitialized, picking up the new class.

     This case is treated the same as changing an existing class. The difference is that adding the servlet or class does not immediately cause the Web application to reload because the class has never been loaded before. The class simply becomes available for execution.

  2. If automatic reloading is not enabled, restart the application. Use the console to restart the application. Or run the wasadmin stopApplication and startApplication commands.

     If automatic reloading is enabled, you do not need to take further action. Automatic reloading will detect the change.

• Add a new servlet, including a new definition of the servlet in the web.xml deployment descriptor for the application.

  1. Place the new .class file directly in the application_root/module_name/WEB-INF/classes directory. If the .class file is part of a Jar file, you can place the new version of the Jar file directly in application_root/module_name/WEB-INF/lib.

     You can edit the web.xml file in place or copy it into the application_root/module_name/WEB-INF/classes directory. The new .class file will not trigger a reloading of the application.

  2. Restart the application.

     Use the administrative console to restart the application. Or run the wasadmin stopApplication and startApplication commands. After the application restarts, the new servlet is available for service.

• Change the web.xml file of a WAR file.

  1. Edit the web.xml file in place or copy it into the metadata_root/module_name/WEB-INF directory.

  2. Restart the application.

     Use the administrative console to restart the application. Or run the wasadmin stopApplication and startApplication commands.

• Change the ibm-web-ext.xmi file of a WAR file.

  Edit the extension settings as needed. You can change all of the extension settings. The only warning is if you set the reloadInterval property to zero (0) or the reloadEnabled property to false, the application no longer automatically detects changes to class files. Both of these changes disable the automatic reloading function. The only way to re-enable automatic reloading is to change the appropriate property and restart the application. See other task descriptions in this file for information on restarting an application.

• Change the ibm-web-bnd.xmi file of a WAR file.

  1. Edit the bindings as needed. You can change all of the values but ensure that the entities you are binding to are present in the configuration of the server.

  2. Restart the application.

     Use the administrative console to restart the application. Or run the wasadmin stopApplication and startApplication commands.

---

Hot deployment and dynamic reloading
Start applications with scripting
Stopping applications with scripting