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1. # Doing work at server startup and shutdown I. Introduction II. Using startup and shutdown classes Startup classes Writing startup classes Registering startup classes Shutdown classes # I. Introduction WebLogic provides a mechanism for performing tasks when the WebLogic Server starts up or is gracefully shut down. Your server-side application may perform any task from a Java class, which has access to all of WebLogic's server-side services. An example use might be to set up an triggered action that's performed at regular intervals throughout the life of the server. # II. Using startup and shutdown classes ## Startup classes To perform a task when the WebLogic Server is started, you write a startup class and register it in the weblogic.properties file. Startup classes are automatically loaded and executed when the WebLogic Server is started, or restarted. Startup classes are only loaded and invoked after all other server initialization has completed. ### Writing startup classes Follow these steps to write a startup class: Your startup class must implement the interface weblogic.common.T3StartupDef. It must implement the startup() method, and the setServices() method. Additionally, your class must have a public default constructor. Here is a template of the startup class with comments where you add your own code:
       import java.util.Hashtable;
       import weblogic.common.*;

       public class MyStartup implements T3StartupDef {

         public StartupTest() {}

         private T3ServicesDef services;

         public void setServices(T3ServicesDef services) {
           this.services = services;
         }

         public String startup(String name, Hashtable args) throws Exception {
           // Write your startup code here...
           return "ok";
         }

       }
2. The startup() method takes two arguments, defined here: String name A String holding the name of the startup class as registered in the weblogic.properties file. You can incorporate this into your startup class logic to create a reusable class that is uniquely identified by its virtual name in the properties file. Hashtable args A Hashtable containing the initialization arguments, registered in the weblogic.properties file. You can use the startup arguments to allow the logic of your startup class to be configured at deployment time. The startup() method must return a String that is written to the WebLogic log file. The setServices() method is invoked prior to the startup() method. Your startup class can store a reference to the T3ServicesDef object factory, so that it had access to the WebLogic services directly, without requireing a JNDI lookup. Set up your development environment, as described in Setting your development environment. Now, compile the startup class and place it under the classpath directory pointed to by the environment variable SERVER_CLASSES. This directory is included in the server classpath. Here is an example compile line on NT:
        $  javac -d %SERVER_CLASSES% MyStartup.java
Register your startup class in the weblogic.properties file. See the Administrators Guide section Registering startup and shutdown classes for details. Start the WebLogic Server. Your startup class is invoked after the server has completely initialized, but immediately before the server begins listening on its TCP/IP listen port. The startup class is guaranteed to run before the WebLogic Server starts servicing clients. # Shutdown classes weblogic.common.T3ShutdownDef Shutdown classes work the same way as start up classes. Shutdown operations are automatically loaded and executed when the WebLogic Server is shutdown with the weblogic.Admin shutdown command. You write a shutdown class by implementing the interface weblogic.common.T3ShutdownDef. Shutdown functions might include such things as writing a message to the log file or cleaning up resources. Details on registering a shutdown class can be found in the Administrators Guide, under the section Registering startup and shutdown classes.

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