oracle.jbo.common.ampool
Interface ApplicationPool

All Known Implementing Classes:

ApplicationPoolImpl

public interface ApplicationPool

This is the ApplicationPool interface. It needs to be implemented by any class that is intended to provide a customized pool interface. Look at ApplicationPoolImpl for the default implementation.
View Implementation of ApplicationPool View Implementation of ApplicationPoolImpl

Method Summary

void	checkin(ApplicationModule instance) Checks in an application instance that had previously been checked out.
java.lang.String	checkinWithSessionState(ApplicationModule appModule) Check-in the application module as being referenced by the invoking session thread.
ApplicationModule	checkout() Checks out an application instance from the pool.
ApplicationModule	checkout(java.lang.String sessionId) Returns an application module for the specified session id.
void	commitAndSyncCache(ApplicationModule instance) Given an intitial Application Module instance, synchronizes the caches of all Application Module instances in the pool.
ApplicationModule	createNewInstance() Creates a new instance of an application without looking for an available instance in the pool.
java.lang.String	getApplicationModuleClass() Return the class name of the application modules being managed by the pool.
int	getAvailableNumPools() Gets the snapshot of available number of pools returns number of available pools
java.lang.String	getConnectString() Return the connect string of the application modules being managed by the application pool.
long	getCreationTimeMillis(ApplicationModule instance) Gets the time when the app module was created (in milli-secs).
java.util.Hashtable	getEnvironment() Returns the Hashtable that was used to initialie the Contect for the application modules.
ApplicationModule	getInstance(int nIndex) Returns the application instance represented by the instance index.
int	getInstanceCount() Returns the number of instances that the Application Pool has created.
java.lang.String	getPassword() Returns the password.
java.lang.String	getPoolName() Returns the pool's name.
long	getTimeToCreateMillis(ApplicationModule instance) Gets the time that it will tke to create the application module (in milli-secs).
java.util.Hashtable	getUserData() Returns the User Data hashtable.
java.lang.String	getUserName() Returns the user name.
void	initialize(java.lang.String sPoolName, java.lang.String sApplicationModule, java.lang.String sConnectString, java.util.Hashtable env) This initializes the ApplicationPool.
boolean	isAvailable(ApplicationModule instance) Indicates whether this application module is available.
void	releaseInstances() Causes the pool to release all the application isntances that have been created so far.
void	setAvailable(ApplicationModule instance, boolean bSet) Sets the instance to available or not
void	setPassword(java.lang.String sPassword)
void	setUserData(java.util.Hashtable data) Replaces the userData with the new Hashtable.
void	setUserName(java.lang.String sUser)

Method Detail

initialize

public void initialize(java.lang.String sPoolName,
                       java.lang.String sApplicationModule,
                       java.lang.String sConnectString,
                       java.util.Hashtable env)
                throws java.lang.Exception

This initializes the ApplicationPool. The Pool name should be unique with respect to any other pools. An exception will be thrown on any errors such as duplicate pool name or mismatched information within the connectInfo parameter. Take a close look at the ConnectionInfo documentation since it controls the key information for initializing the application pool.

Parameters:

sPoolName - the name of the application module pool.

sApplicationModule - name of the application module for which the pool will be created.

sConnectString - the connection string to use to connect to the database.

env - name of the hash table containing the environment variables for the selected platform.

getApplicationModuleClass

public java.lang.String getApplicationModuleClass()

Return the class name of the application modules being managed by the pool.

getConnectString

public java.lang.String getConnectString()

Return the connect string of the application modules being managed by the application pool.

getEnvironment

public java.util.Hashtable getEnvironment()

Returns the Hashtable that was used to initialie the Contect for the application modules.

checkin

public void checkin(ApplicationModule instance)

Checks in an application instance that had previously been checked out. This makes the application instance avalable for subsequent checkout requests from this pool.

Parameters:

instance - name of the application module instance to check in.

checkinWithSessionState

public java.lang.String checkinWithSessionState(ApplicationModule appModule)

Check-in the application module as being referenced by the invoking session thread.

This method should be used by pool clients that wish to maintain logical application module state while still sharing an application module resource across requests. The method returns a system generated session id for the check-in that should be used as the unique application module identifier by the client session.

The application module will be passivated immediately if failover support has been requested (default). If failover support has been disable, through the jbo.DoFailover system parameter, the application module will not be passivated until it is re-used by a session other than the session checking in the application module.

Parameters:

appModule - the application module that will be checked in

isAvailable

public boolean isAvailable(ApplicationModule instance)

Indicates whether this application module is available.

Parameters:

instance - the application module instance that you want to test for availability.

Returns:

true if the application module is available; false otherwise.

setAvailable

public void setAvailable(ApplicationModule instance,
                         boolean bSet)

Sets the instance to available or not

checkout

public ApplicationModule checkout()
                           throws java.lang.Exception

Checks out an application instance from the pool. If the pool doesn't have any available instances, it will create a new instance and return it to the caller.

checkout

public ApplicationModule checkout(java.lang.String sessionId)

Returns an application module for the specified session id. The session id must have been generated by a previous call to checkinWithSessionState(ApplicationModule) against this application module pool.

The session id will be used to obtain an application module with the same state as the application module that had been returned by the session with checkinWithSessionState.

If an unrecognized session id is specified than the implementation returns an empty application module.

Parameters:

sessionId - the name of the session ID for which you want to return the associated application module.

releaseInstances

public void releaseInstances()

Causes the pool to release all the application isntances that have been created so far. The remove() method is called on the Application Modules being represented by the application instance class

getInstanceCount

public int getInstanceCount()

Returns the number of instances that the Application Pool has created.

createNewInstance

public ApplicationModule createNewInstance()
                                    throws java.lang.Exception

Creates a new instance of an application without looking for an available instance in the pool. This method should not be called directly, you should call checkout() instead.

getInstance

public ApplicationModule getInstance(int nIndex)

Returns the application instance represented by the instance index.

Parameters:

nIndex - the index of the application instance.

getPoolName

public java.lang.String getPoolName()

Returns the pool's name.

getUserData

public java.util.Hashtable getUserData()

Returns the User Data hashtable. This is a generic container for any settings the user would like to associate with this application pool.

setUserData

public void setUserData(java.util.Hashtable data)

Replaces the userData with the new Hashtable.

Parameters:

the - new hashtable to use for the environment information.

getAvailableNumPools

public int getAvailableNumPools()

Gets the snapshot of available number of pools returns number of available pools

getTimeToCreateMillis

public long getTimeToCreateMillis(ApplicationModule instance)

Gets the time that it will tke to create the application module (in milli-secs).

Parameters:

instance - the application module instance for which you want to know how long it will take to create it.

getCreationTimeMillis

public long getCreationTimeMillis(ApplicationModule instance)

Gets the time when the app module was created (in milli-secs).

Parameters:

instance - the application module instance for which you want to know the time of creation.

getUserName

public java.lang.String getUserName()

Returns the user name.

getPassword

public java.lang.String getPassword()

Returns the password.

setUserName

public void setUserName(java.lang.String sUser)

setPassword

public void setPassword(java.lang.String sPassword)

commitAndSyncCache

public void commitAndSyncCache(ApplicationModule instance)

Given an intitial Application Module instance, synchronizes the caches of all Application Module instances in the pool.

This method commits the transaction for instance. Then, it loops through all other instances of the Application Module in the pool and synchronizes their caches with the changes committed by instance. For example:

  // Insert a new row
     row = voEmp1.createRow();

     row.setAttribute("EmpNum", new Integer(9999));
     row.setAttribute("EmpName", "NewPers");
     row.setAttribute("EmpJob", "JOBX");

     voEmp1.insertRow(row);

  // Commit the changes for the specified instance, then sync 
  // them with the rest of the Application Module instances.
     pool1.commitAndSyncCache(am1);
 

Parameters:

instance - an instance of an Application Module in the pool.