com.kabira.store

Class Query<T>

java.lang.Object

com.kabira.store.Query<T>

@Managed
public abstract class Query<T>
extends java.lang.Object

Class for receiving notifications of KeyQuery results calls.

A Query notifier does not directly return results. The notification provides an opportunity to change the contents of shared memory (creating and or deleting Managed objects) before a keyed query is done. For example, it could be used for creating Managed objects from data in a database.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Query(java.lang.Class<T> klass, java.lang.String keyName) Constructor.

Method Summary

Modifier and Type	Method and Description
java.lang.String	getKeyName() Get the name of the key for this Query notifier.
static Query<?>	getNotifier(java.lang.Class<?> klass, java.lang.String key) Return the currently installed Query notifier for the Managed class and key.
abstract void	query(java.lang.Class<? extends T> klass, LockMode lockMode, java.util.ArrayList<KeyField> queryData) Notifier method for KeyQuery results calls.
abstract void	queryMaximum(java.lang.Class<? extends T> klass, LockMode lockMode, java.util.ArrayList<KeyField> queryData) Notifier method for KeyQuery.getMaximumResult(com.kabira.platform.LockMode) calls.
abstract void	queryMinimum(java.lang.Class<? extends T> klass, LockMode lockMode, java.util.ArrayList<KeyField> queryData) Notifier method for KeyQuery.getMinimumResult(com.kabira.platform.LockMode) calls.

Methods inherited from class java.lang.Object

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

Constructor Detail

Query

protected Query(java.lang.Class<T> klass,
                java.lang.String keyName)
         throws ManagedClassError,
                KeyUnknownKeyNameError

Constructor.

Creating an instance automatically installs it as the query notifier for the associated Managed class and key.

A notifier may only be set on the class where the key is defined.

The notifier will apply to queries on the class where the key is defined, and queries on classes which inherit the key.

If a notifier is already installed for the key, the new instance replaces the previous instance.

Deleting a notifier automatically uninstalls it.

Notifiers are automatically deleted when the JVM shuts down. Notifiers created in other JVMs are not affected.

When a KeyQuery results method is called, the Query notifier for the key will be called before executing the query.

Parameters:

klass - The Managed class where keyName is defined.

keyName - The key to receive query notifications for.

Throws:

ManagedClassError - If klass is not managed.

KeyUnknownKeyNameError - if keyName is not defined on klass.

Method Detail

getNotifier

public static Query<?> getNotifier(java.lang.Class<?> klass,
                                   java.lang.String key)

Return the currently installed Query notifier for the Managed class and key.

Inheritance is not examined by this method.

Parameters:

klass - Class where key is defined.

key - Name of key.

Returns:

Query or null.

Throws:

ManagedClassError - If klass is not managed.

KeyUnknownKeyNameError - If keyName is not defined on klass.

getKeyName

public final java.lang.String getKeyName()

Get the name of the key for this Query notifier.

Returns:

Key name.

query

public abstract void query(java.lang.Class<? extends T> klass,
                           LockMode lockMode,
                           java.util.ArrayList<KeyField> queryData)

Notifier method for KeyQuery results calls.

Called by the system when following KeyQuery methods are called, but before they are executed:

KeyQuery.getOrCreateSingleResult(com.kabira.platform.LockMode, com.kabira.platform.KeyFieldValueList) - for unique keys

KeyQuery.getSingleResult(com.kabira.platform.LockMode) - for unique keys

KeyQuery.getResults(com.kabira.platform.LockMode) - for non unique keys

KeyOrderedBy does not need to be considered by the notifier. Result set ordering is handled by the runtime when the query executes.

Will be called on each of the nodes in the QueryScope of the KeyQuery results call.

Work done within Query.query() will not generate calls to com.kabira.store notifiers on the local node.

Note: work done within the Query.query() method will generate calls to com.kabira.store notifiers on remote nodes.

Parameters:

klass - The Managed class for the query results call. This may be a subtype of the class associated with the notifier.

lockMode - The lock mode for the query results. The notifier implementation should attempt to honor this lock mode, but there is no enforcement.

queryData - The query data, ordered as the caller added it to the KeyFieldValueList or KeyFieldValueRangeList for the query. See KeyField.

queryMinimum

public abstract void queryMinimum(java.lang.Class<? extends T> klass,
                                  LockMode lockMode,
                                  java.util.ArrayList<KeyField> queryData)

Notifier method for KeyQuery.getMinimumResult(com.kabira.platform.LockMode) calls.

Called by the system when KeyQuery.getMinimumResult is called, but before it is executed.

Will be called on each of the nodes in the QueryScope of getMinimumResult call.

Work done within Query.queryMinimum() will not generate calls to com.kabira.store notifiers on the local node.

Note: work done within Query.queryMinimum() will generate calls to com.kabira.store notifiers on remote nodes.

Parameters:

klass - The Managed class for the getMinimumResult call. This may be a subtype of the class associated with the notifier.

lockMode - The lock mode for the query result. The notifier implementation should attempt to honor this lock mode, but there is no enforcement.

queryData - The query data, ordered as the caller added it to the KeyFieldValueList or KeyFieldValueRangeList for the query. See KeyField.

queryMaximum

public abstract void queryMaximum(java.lang.Class<? extends T> klass,
                                  LockMode lockMode,
                                  java.util.ArrayList<KeyField> queryData)

Notifier method for KeyQuery.getMaximumResult(com.kabira.platform.LockMode) calls.

Called by the system when KeyQuery.getMaximumResult is called, but before it is executed.

Will be called on each of the nodes in the QueryScope of getMaximumResult call.

Work done within Query.queryMaximum() will not generate calls to com.kabira.store notifiers on the local node.

Note: work done within Query.queryMaximum() will generate calls to com.kabira.store notifiers on remote nodes.

Parameters:

klass - The Managed class for the getMaximumResult call. This may be a subtype of the class associated with the notifier.

lockMode - The lock mode for the query result. The notifier implementation should attempt to honor this lock mode, but there is no enforcement.

queryData - The query data, ordered as the caller added it to the KeyFieldValueList or KeyFieldValueRangeList for the query. See KeyField.