org.apache.avalon.cornerstone.blocks.datasources
Class DefaultDataSourceSelector

java.lang.Object
  org.apache.avalon.framework.logger.AbstractLogEnabled
      org.apache.avalon.cornerstone.blocks.datasources.DefaultDataSourceSelector

All Implemented Interfaces:

Configurable, Contextualizable, DataSourceSelector, Disposable, Initializable, LogEnabled, ServiceSelector

public class DefaultDataSourceSelector

extends AbstractLogEnabled

implements DataSourceSelector, Contextualizable, Configurable, Initializable, Disposable

A default implementation for DataSourceSelector. The Configuration is like this:

 <myBlock>
   <data-source name="default"
     class="org.apache.avalon.excalibur.datasource.JdbcDataSource">
     <!-- configuration for JdbcDataSource -->
     <pool-controller min="5" max="10" connection-class="my.overrided.ConnectionClass">
       <keep-alive>select 1</keep-alive>
     </pool-controller>
     <driver>com.database.jdbc.JdbcDriver</driver>
     <dburl>jdbc:driver://host/mydb</dburl>
     <user>username</user>
     <password>password</password>
   </data-source>
 </myBlock>
 

Author:

Avalon Development Team

Field Summary

Fields inherited from interface org.apache.avalon.cornerstone.services.datasources.DataSourceSelector

ROLE

Constructor Summary

DefaultDataSourceSelector()

Method Summary

void	configure(Configuration configuration) Pass the Configuration to the Configurable class.
void	contextualize(Context context) Contextualization of the component by the container.
void	dispose() The dispose operation is called at the end of a components lifecycle.
void	initialize() Initialize the component.
boolean	isSelectable(java.lang.Object hint) Check to see if a Object exists relative to the supplied policy.
void	release(java.lang.Object component) Return the Object when you are finished with it.
java.lang.Object	select(java.lang.Object hint) Select the Object associated with the given policy.

Methods inherited from class org.apache.avalon.framework.logger.AbstractLogEnabled

enableLogging, getLogger, setupLogger, setupLogger, setupLogger

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DefaultDataSourceSelector

public DefaultDataSourceSelector()

Method Detail

contextualize

public void contextualize(Context context)
                   throws ContextException

Contextualization of the component by the container.

Specified by:

contextualize in interface Contextualizable

Parameters:

context - the supplied context object

Throws:

ContextException - if context is invalid

configure

public void configure(Configuration configuration)

Description copied from interface: Configurable

Pass the Configuration to the Configurable class.

Specified by:

configure in interface Configurable

Parameters:

configuration - the class configurations. Must not be null.

initialize

public void initialize()
                throws java.lang.Exception

Description copied from interface: Initializable

Initialize the component. Initialization includes allocating any resources required throughout the component's lifecycle.

Specified by:

initialize in interface Initializable

Throws:

java.lang.Exception - if an error occurs

dispose

public void dispose()

Description copied from interface: Disposable

The dispose operation is called at the end of a components lifecycle. This method will be called after Startable.stop() method (if implemented by component). Components use this method to release and destroy any resources that the Component owns.

Specified by:

dispose in interface Disposable

isSelectable

public boolean isSelectable(java.lang.Object hint)

Description copied from interface: ServiceSelector

Check to see if a Object exists relative to the supplied policy.

Specified by:

isSelectable in interface ServiceSelector

Parameters:

hint - a Object containing the selection criteria

Returns:

True if the component is available, False if it not.

select

public java.lang.Object select(java.lang.Object hint)
                        throws ServiceException

Description copied from interface: ServiceSelector

Select the Object associated with the given policy. For instance, If the ServiceSelector has a Generator stored and referenced by a URL, the following call could be used:

 try
 {
     Generator input;
     input = (Generator)selector.select( new URL("foo://demo/url") );
 }
 catch (...)
 {
     ...
 }
 

Specified by:

select in interface ServiceSelector

Parameters:

hint - A criteria against which a Object is selected.

Returns:

an Object value

Throws:

ServiceException - If the requested Object cannot be supplied

release

public void release(java.lang.Object component)

Description copied from interface: ServiceSelector

Return the Object when you are finished with it. This allows the ServiceSelector to handle the End-Of-Life Lifecycle events associated with the Object. Please note, that no Exception should be thrown at this point. This is to allow easy use of the ServiceSelector system without having to trap Exceptions on a release.

Specified by:

release in interface ServiceSelector

Parameters:

component - The Object we are releasing, may also be a null reference