org.datanucleus.store.rdbms.query
Class ForwardQueryResult

java.lang.Object
  java.util.AbstractCollection<E>
      java.util.AbstractList
          org.datanucleus.store.query.AbstractQueryResult
              org.datanucleus.store.rdbms.query.AbstractRDBMSQueryResult
                  org.datanucleus.store.rdbms.query.ForwardQueryResult

All Implemented Interfaces:

java.io.Serializable, java.lang.Iterable, java.util.Collection, java.util.List, org.datanucleus.store.query.QueryResult

public final class ForwardQueryResult
extends AbstractRDBMSQueryResult

Lazy collection results from a Query with the ResultSet in a forwards direction. In general the actual result elements are only loaded when accessed with the exception of non-transactional or optimistic contexts that load the elements at initialisation.

See Also:

Serialized Form

Field Summary

protected boolean	moreResultSetRows Whether there are still more rows to be processed in the ResultSet.
protected java.util.List	resultObjs The Result Objects.

Fields inherited from class org.datanucleus.store.rdbms.query.AbstractRDBMSQueryResult

rof, rs

Fields inherited from class org.datanucleus.store.query.AbstractQueryResult

closed, connectionListeners, loadResultsAtCommit, LOCALISER, query, resultSizeMethod, size

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

ForwardQueryResult(org.datanucleus.store.query.Query query, org.datanucleus.store.query.ResultObjectFactory rof, java.sql.ResultSet rs, java.util.Collection candidates)
Constructor of the result from a Query.

Method Summary

void	close() Method to close the results, making the results unusable thereafter.
protected void	closingConnection() Method called to inform the query result that the connection is being closed so perform any required operations now, or rest in peace.
boolean	contains(java.lang.Object o) Method to check if the specified object is contained in this result.
boolean	containsAll(java.util.Collection c) Method to check if all of the specified objects are contained here.
boolean	equals(java.lang.Object o) Equality operator for QueryResults.
java.lang.Object	get(int index) Method to retrieve a particular element from the list.
protected int	getSizeUsingMethod() Method to get the size using the "resultSizeMethod".
boolean	isEmpty() Returns true if this collection contains no elements.
java.util.Iterator	iterator() Accessor for an iterator for the results.
java.util.ListIterator	listIterator() Accessor for an iterator for the results.
protected java.lang.Object	nextResultSetElement() Accessor for the next object from the ResultSet.
java.lang.Object[]	toArray() Method to return the results as an array.
java.lang.Object[]	toArray(java.lang.Object[] a) Method to return the results as an array.

Methods inherited from class org.datanucleus.store.rdbms.query.AbstractRDBMSQueryResult

closeResults, disconnect, getSizeUsingCount, hashCode

Methods inherited from class org.datanucleus.store.query.AbstractQueryResult

add, add, addAll, addConnectionListener, assertIsOpen, clear, indexOf, isOpen, lastIndexOf, remove, set, size, subList

Methods inherited from class java.util.AbstractList

listIterator, removeRange

Methods inherited from class java.util.AbstractCollection

addAll, remove, removeAll, retainAll, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

addAll, remove, removeAll, retainAll

Methods inherited from interface java.util.List

addAll, remove, removeAll, retainAll

Field Detail

moreResultSetRows

protected boolean moreResultSetRows

Whether there are still more rows to be processed in the ResultSet.

resultObjs

protected java.util.List resultObjs

The Result Objects.

Constructor Detail

ForwardQueryResult

public ForwardQueryResult(org.datanucleus.store.query.Query query,
                          org.datanucleus.store.query.ResultObjectFactory rof,
                          java.sql.ResultSet rs,
                          java.util.Collection candidates)
                   throws java.sql.SQLException

Constructor of the result from a Query.

Parameters:

query - The Query

rof - The factory to retrieve results from

rs - The ResultSet from the Query Statement

candidates - Candidate elements. Pass this argument only when distinct = false

Throws:

java.sql.SQLException - if can't read ResultSet

Method Detail

nextResultSetElement

protected java.lang.Object nextResultSetElement()

Accessor for the next object from the ResultSet.

Returns:

The next element from the ResultSet.

close

public void close()

Method to close the results, making the results unusable thereafter.

Specified by:

close in interface org.datanucleus.store.query.QueryResult

Overrides:

close in class AbstractRDBMSQueryResult

closingConnection

protected void closingConnection()

Method called to inform the query result that the connection is being closed so perform any required operations now, or rest in peace.

Specified by:

closingConnection in class org.datanucleus.store.query.AbstractQueryResult

iterator

public java.util.Iterator iterator()

Accessor for an iterator for the results.

Specified by:

iterator in interface java.lang.Iterable

Specified by:

iterator in interface java.util.Collection

Specified by:

iterator in interface java.util.List

Specified by:

iterator in class org.datanucleus.store.query.AbstractQueryResult

Returns:

The iterator

listIterator

public java.util.ListIterator listIterator()

Accessor for an iterator for the results.

Specified by:

listIterator in interface java.util.List

Specified by:

listIterator in class org.datanucleus.store.query.AbstractQueryResult

Returns:

The iterator

contains

public boolean contains(java.lang.Object o)

Method to check if the specified object is contained in this result.

Specified by:

contains in interface java.util.Collection

Specified by:

contains in interface java.util.List

Overrides:

contains in class org.datanucleus.store.query.AbstractQueryResult

Parameters:

o - The object

Returns:

Whether it is contained here.

containsAll

public boolean containsAll(java.util.Collection c)

Method to check if all of the specified objects are contained here.

Specified by:

containsAll in interface java.util.Collection

Specified by:

containsAll in interface java.util.List

Overrides:

containsAll in class org.datanucleus.store.query.AbstractQueryResult

Parameters:

c - The collection of objects

Returns:

Whether they are all contained here.

equals

public boolean equals(java.lang.Object o)

Equality operator for QueryResults. Overrides the AbstractList implementation since that uses size() and iterator() and that would cause problems when closed.

Specified by:

equals in interface java.util.Collection

Specified by:

equals in interface java.util.List

Specified by:

equals in class org.datanucleus.store.query.AbstractQueryResult

Parameters:

o - The object to compare against

Returns:

Whether they are equal

get

public java.lang.Object get(int index)

Method to retrieve a particular element from the list.

Specified by:

get in interface java.util.List

Specified by:

get in class org.datanucleus.store.query.AbstractQueryResult

Parameters:

index - The index of the element

Returns:

The element at index

isEmpty

public boolean isEmpty()

Returns true if this collection contains no elements.

This implementation check if the result is empty.

Specified by:

isEmpty in interface java.util.Collection

Specified by:

isEmpty in interface java.util.List

Overrides:

isEmpty in class org.datanucleus.store.query.AbstractQueryResult

Returns:

true if this collection contains no elements.

getSizeUsingMethod

protected int getSizeUsingMethod()

Method to get the size using the "resultSizeMethod". This implementation supports "LAST" method. Override this in subclasses to implement other methods.

Overrides:

getSizeUsingMethod in class org.datanucleus.store.query.AbstractQueryResult

Returns:

The size

toArray

public java.lang.Object[] toArray()

Method to return the results as an array.

Specified by:

toArray in interface java.util.Collection

Specified by:

toArray in interface java.util.List

Overrides:

toArray in class org.datanucleus.store.query.AbstractQueryResult

Returns:

The array.

toArray

public java.lang.Object[] toArray(java.lang.Object[] a)

Method to return the results as an array.

Specified by:

toArray in interface java.util.Collection

Specified by:

toArray in interface java.util.List

Overrides:

toArray in class org.datanucleus.store.query.AbstractQueryResult

Parameters:

a - The array to copy into.

Returns:

The array.