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Class examples.t3client.StartupQuery

java.lang.Object
   |
   +----examples.t3client.StartupQuery

public class StartupQuery

extends Object

implements T3ServletDef, T3StartupDef

• Startup classes are automatically loaded and executed when the WebLogic Server starts up. You can use startup classes to perform functions that need to run when a WebLogic-based application is launched. In this example we perform JDBC queries that will be used to populate listboxes on GUI.

• Workspaces are hierarchical storage areas in WebLogic that can be shared among WebLogic components, such as WebLogic Event services action and evaluate methods, WebLogic Remote T3Servlets, and T3Startup classes. In this example, we use a Workspace to store the results of a JDBC query.

• T3Servlets are methods that can be invoked by T3Clients within the WebLogic Server. In this example, we use a T3Servlet to retrieve the results of the JDBC query from the Workspace.

This example requres a Cloudscape database instance. You'll need to register this class as a startup class in your weblogic.properties file, as detailed in the description of the startup() method.

StartupQuery()

declareParams(ParamSet)

This method implements the WebLogic T3Servlet interface.

execute(ParamSet)

This method implements the WebLogic T3Servlet interface.

setServices(T3ServicesDef)

This method implements the WebLogic T3Servlet interface.

startup(String, Hashtable)

The startup() method is called at WebLogic startup, as a result of placing the following lines in the weblogic.properties file:

weblogic.system.startupClass.doquery=examples.t3client.StartupQuery
    weblogic.system.startupArgs.doquery=\
    query=select * from emp,\
    db=jdbc:weblogic:pool:demoPool

where "db" is the URL of your database pool that contains a table that you include in the arg "query".

 public StartupQuery()

 public String startup(String name,
                       Hashtable args) throws Exception

The startup() method is called at WebLogic startup, as a result of placing the following lines in the weblogic.properties file:

weblogic.system.startupClass.doquery=examples.t3client.StartupQuery
    weblogic.system.startupArgs.doquery=\
    query=select * from emp,\
    db=jdbc:weblogic:pool:demoPool

where "db" is the URL of your database pool that contains a table that you include in the arg "query".

When startup is invoked as a result of these two lines, the "name" argument will be "doquery" (from the left-hand of the property), and the args hashtable will contain the name-value pair "query", "select * from emp".

 public void setServices(T3ServicesDef services)

This method implements the WebLogic T3Servlet interface.

The setServices() method is called to pass to the T3Servlet the handle of an object that can be used to access WebLogic services. This makes another reference to the services object so it can be used later.

Parameters:

services - Services stub

 public void declareParams(ParamSet ps) throws ParamSetException

This method implements the WebLogic T3Servlet interface.

The declareParams() method is called to specify the parameters that this T3Servlet will accept. WebLogic calls this method when the server-side object is instantiated.

Parameters:

ps - ParamSet

Throws: ParamSetException

if there is an error in the ParamSet

 public void execute(ParamSet ps) throws Exception

This method implements the WebLogic T3Servlet interface.

The execute() method is called when the client requests the invocation of this servlet. the ParamSet contains the arguments for the execute() method.

Parameters:

ps - ParamSet

Throws: Exception

if there is an error in execution

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