com.programix.da2.bridge
Class DABridgeProxy

java.lang.Object
  com.programix.da2.bridge.DABridgeProxy

All Implemented Interfaces:

DASource

public class DABridgeProxy
extends Object
implements DASource

This part of the Data Access Bridge system is a DASource that converts requests to be sent to the DABridgeProcessor supplied at construction.

NOTE: Neither the init() method nor the the shutdown() method are permitted to be remotely. Calling init() on any DA's retrieved from this proxy will result in a DABridgeDAException being thrown. Calling shutdown() on any DA's retrieved from this proxy will silently do nothing.

Author:

Paul Hyde

Constructor Summary

DABridgeProxy(DABridgeProcessor processor)

Method Summary

<T extends GenericDA> T	getDA(Class<T> daInterfaceType) Searches for an implementation of the specified interface type.
boolean	isAvailable(Class<? extends GenericDA> daInterfaceType) Searches for an implementation of the specified interface type and returns true if one is available.
void	shutdown() This should be called when the DASource is no longer needed to clean up any potential resources being used behind the scenes.

Methods inherited from class java.lang.Object

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

Constructor Detail

DABridgeProxy

public DABridgeProxy(DABridgeProcessor processor)
              throws DAException

Throws:

DAException

Method Detail

getDA

public <T extends GenericDA> T getDA(Class<T> daInterfaceType)
                          throws DAException

Description copied from interface: DASource

Searches for an implementation of the specified interface type.

Specified by:

getDA in interface DASource

Parameters:

daInterfaceType - the interface type for which an implementation is desired.

Returns:

an implementation of the specified type.

Throws:

DAException - if either no implementation can be found or if there is trouble creating/accessing the implementation.

isAvailable

public boolean isAvailable(Class<? extends GenericDA> daInterfaceType)
                    throws DAException

Description copied from interface: DASource

Searches for an implementation of the specified interface type and returns true if one is available. If this method returns true, then calling DASource.getDA(Class) with the same parameter is virtually guaranteed to succeed (barring a communication breakdown, a call to shutdown, or similar unforeseen problems).

Specified by:

isAvailable in interface DASource

Parameters:

daInterfaceType - the interface type for which an implementation is desired.

Returns:

true if an implementation is available, false if not.

Throws:

DAException - if a determination can not be made (perhaps because of a communication error or other similar kinds of problems that prevent a definitive answer from being found).

shutdown

public void shutdown()

Description copied from interface: DASource

This should be called when the DASource is no longer needed to clean up any potential resources being used behind the scenes. Some implementations may have nothing to do when shutdown, but other implementations might have important deallocation duties to perform.

If there are any "cached" instances of GenericDA that this source is holding, those are individually shutdown by calling this method.

No other methods should be called after this method. Calling other methods after calling this method results in undefined behavior (many times, a ShutdownDAException will be thrown when attempting to invoke those other methods, but there is no requirement that all methods do this).

Calling shutdown() more than one time must be allowed and shutdown() must not complain. Also note that shutdown() never throws any exceptions—it just makes its best effort of close down everything. Implementations must assure that this remains true.

Specified by:

shutdown in interface DASource