de.mguennewig.pobjects
Class PObjMap<T extends Record>

java.lang.Object
  de.mguennewig.pobjects.AbstractPObjJoin<T>
      de.mguennewig.pobjects.PObjMap<T>

public class PObjMap<T extends Record>
extends AbstractPObjJoin<T>

Wrapper object for map valued joins between two tables.

Please note that the methods of this class resemble that of the standard collection class Map, but that the semantics usually differ to some degree. In particular, every method call is an operation on the RDBMS, and the backing store's semantics do not follow those of Java. For example, given statement level read consistency on the RDBMS, a size() followed by a findAll().length may produce different results.

Even thought the methods of this map are synchronized is there still the chance for concurrent modifications made by other database users.

Author:

Michael Günnewig

Constructor Summary

PObjMap(PObject parent, java.lang.Class<? extends Record> elementClass)
Creates a new map.

Method Summary

boolean	containsKey(java.lang.Object... key) Return true if the given key exists in this map.
T	get(java.lang.Object... key) Return the map element matching the given key, or null if no such row exists.
T	put(java.lang.Object... keyValues) Add the given arguments as an element to the map.
T	putIfAbsent(java.lang.Object... keyValues) If the specified key is not already associated with a value, associate it with the given value.
boolean	remove(java.lang.Object... key) Remove the given arguments as an element from the map.
boolean	remove(T obj) Remove the give record obj as an element from the map.

Methods inherited from class de.mguennewig.pobjects.AbstractPObjJoin

clear, findAll, getContainer, getElementClass, getElementDecl, getParent, isEmpty, size

Methods inherited from class java.lang.Object

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

Constructor Detail

PObjMap

public PObjMap(PObject parent,
               java.lang.Class<? extends Record> elementClass)

Creates a new map.

Method Detail

get

public T get(java.lang.Object... key)

Return the map element matching the given key, or null if no such row exists.

Throws:

java.lang.IllegalArgumentException - if key.length != pk.length-1.

containsKey

public boolean containsKey(java.lang.Object... key)

Return true if the given key exists in this map.

Throws:

java.lang.IllegalArgumentException - if key.length != pk.length-1.

put

public T put(java.lang.Object... keyValues)
                     throws PObjConstraintException,
                            PObjSQLException

Add the given arguments as an element to the map. It is an error if the element already exists. The data is stored immediately in the RDBMS. In this, the put() method resembles store() on a newly created PObject.

Parameters:

keyValues - the list of keys followed by the list of values

Returns:

The old value associated to the key or null if the key didn't exist before.

Throws:

PObjConstraintException

PObjSQLException

putIfAbsent

public final T putIfAbsent(java.lang.Object... keyValues)
                                   throws PObjConstraintException,
                                          PObjSQLException

If the specified key is not already associated with a value, associate it with the given value.

Parameters:

keyValues - the list of keys followed by the list of values

Returns:

The old value associated to the key or null if the key didn't exist before.

Throws:

PObjConstraintException

PObjSQLException

See Also:

get(Object[]), put(Object[])

remove

public boolean remove(T obj)
               throws PObjConstraintException,
                      PObjSQLException

Remove the give record obj as an element from the map. If the element exists prior to the call, then the result is true. The data is stored immediately in the RDBMS. In this, the remove() method resembles store() on a delete PObject.

Throws:

PObjConstraintException

PObjSQLException

remove

public boolean remove(java.lang.Object... key)
               throws PObjConstraintException,
                      PObjSQLException

Remove the given arguments as an element from the map. If the element exists prior to the call, then the result is true. The data is stored immediately in the RDBMS. In this, the put() method resembles store() on a deleted PObject.

Throws:

PObjConstraintException

PObjSQLException