org.apache.derby.impl.sql.conn
Class CachedStatement

java.lang.Object
  org.apache.derby.impl.sql.conn.CachedStatement

All Implemented Interfaces:

Cacheable

public class CachedStatement
extends java.lang.Object
implements Cacheable

Field Summary

private java.lang.Object	identity
private GenericPreparedStatement	ps

Constructor Summary

CachedStatement()

Method Summary

void	clean(boolean forRemove) Clean the object.
void	clearIdentity() Put the object into the No Identity state.
Cacheable	createIdentity(java.lang.Object key, java.lang.Object createParameter) Create a new item.
java.lang.Object	getIdentity() Get the identity of this object.
GenericPreparedStatement	getPreparedStatement() Get the PreparedStatement that is associated with this Cacheable
boolean	isDirty() Returns true of the object is dirty.
Cacheable	setIdentity(java.lang.Object key) Set the identity of the object.

Methods inherited from class java.lang.Object

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

Field Detail

ps

private GenericPreparedStatement ps

identity

private java.lang.Object identity

Constructor Detail

CachedStatement

public CachedStatement()

Method Detail

getPreparedStatement

public GenericPreparedStatement getPreparedStatement()

Get the PreparedStatement that is associated with this Cacheable

clean

public void clean(boolean forRemove)

Description copied from interface: Cacheable

Clean the object. It is up to the object to ensure synchronization of the isDirty() and clean() method calls.
If forRemove is true then the object is being removed due to an explict remove request, in this case the cache manager will have called this method regardless of the state of the isDirty()
If an exception is thrown the object must be left in the clean state.
MT - thread safe - Can be called at any time by the cache manager, it is the responsibility of the object implementing Cacheable to ensure any users of the object do not conflict with the clean call.

Specified by:

clean in interface Cacheable

See Also:

Cacheable.clean(boolean)

setIdentity

public Cacheable setIdentity(java.lang.Object key)

Description copied from interface: Cacheable

Set the identity of the object.

Set the identity of the object to represent an item that already exists, e.g. an existing container. The object will be in the No Identity state, ie. it will have just been created or clearIdentity() was just called.
The object must copy the information out of key, not just store a reference to key. After this call the expression getIdentity().equals(key) must return true.
If the class of the object needs to change (e.g. to support a different format) then the object should create a new object, call its initParameter() with the parameters the original object was called with, set its identity and return a reference to it. The cache manager will discard the reference to the old object.
If an exception is thrown the object must be left in the no-identity state.
MT - single thread required - Method must only be called be cache manager and the cache manager will guarantee only one thread can be calling it.

Specified by:

setIdentity in interface Cacheable

Returns:

an object reference if the object can take on the identity, null otherwise.

See Also:

CacheManager.find(java.lang.Object)

createIdentity

public Cacheable createIdentity(java.lang.Object key,
                                java.lang.Object createParameter)

Description copied from interface: Cacheable

Create a new item.

Create a new item and set the identity of the object to represent it. The object will be in the No Identity state, ie. it will have just been created or clearIdentity() was just called.
The object must copy the information out of key, not just store a reference to key if the key is not immutable. After this call the expression getIdentity().equals(key) must return true.

If the class of the object needs to change (e.g. to support a different format) then the object should create a new object, call its initParameter() with the parameters the original object was called with, set its identity and return a reference to it. The cache manager will discard the reference to the old object.
If an exception is thrown the object must be left in the no-identity state.
MT - single thread required - Method must only be called be cache manager and the cache manager will guarantee only one thread can be calling it.

Specified by:

createIdentity in interface Cacheable

Returns:

an object reference if the object can take on the identity, null otherwise.

See Also:

Cacheable.createIdentity(java.lang.Object, java.lang.Object)

clearIdentity

public void clearIdentity()

Description copied from interface: Cacheable

Put the object into the No Identity state.
MT - single thread required - Method must only be called be cache manager and the cache manager will guarantee only one thread can be calling it.

Specified by:

clearIdentity in interface Cacheable

See Also:

Cacheable.clearIdentity()

getIdentity

public java.lang.Object getIdentity()

Description copied from interface: Cacheable

Get the identity of this object.
MT - thread safe.

Specified by:

getIdentity in interface Cacheable

See Also:

Cacheable.getIdentity()

isDirty

public boolean isDirty()

Description copied from interface: Cacheable

Returns true of the object is dirty. May be called when the object is kept or unkept.
MT - thread safe

Specified by:

isDirty in interface Cacheable

See Also:

Cacheable.isDirty()