org.apache.jdo.query

Class BasicQueryResult

java.lang.Object

org.apache.jdo.query.BasicQueryResult

All Implemented Interfaces:

java.lang.Iterable, java.util.Collection, QueryResult

public class BasicQueryResult
extends java.lang.Object
implements QueryResult

This class implements the basic query execution strategy. It first orders the candidate set using the query helper orderCandidates method. It then iterates over the ordered candidate collection, filtering each one, using the query helper applyFilter method and removing the objects that fail the filter. All of the methods of Collection are then delegated to the result collection.

Version:

1.0

Author:

Craig Russell

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	BasicQueryResult.BasicQueryResultIterator The internal query result iterator supports all iterator methods plus close, allowing early release of resources.

Constructor Summary

Constructors

Constructor and Description
BasicQueryResult(QueryResultHelper qrh) Creates new BasicQueryResult

Method Summary

Methods

Modifier and Type	Method and Description
boolean	add(java.lang.Object obj) This method throws UnsupportedOperationException because the collection is read-only.
boolean	addAll(java.util.Collection collection) This method throws UnsupportedOperationException because the collection is read-only.
void	clear() This method throws UnsupportedOperationException because the collection is read-only.
void	close() This method closes the result set, closes all open iterators, and releases all resources that might be held by the result.
boolean	contains(java.lang.Object obj) This method delegates to the result collection method.
boolean	containsAll(java.util.Collection collection) This method delegates to the result collection method.
boolean	equals(java.lang.Object obj) This method delegates to the result collection method.
int	hashCode() This method delegates to the result collection method.
boolean	isEmpty() This method delegates to the result collection method.
java.util.Iterator	iterator() This method delegates to the result collection method.
boolean	remove(java.lang.Object obj) This method throws UnsupportedOperationException because the collection is read-only.
boolean	removeAll(java.util.Collection collection) This method throws UnsupportedOperationException because the collection is read-only.
boolean	retainAll(java.util.Collection collection) This method throws UnsupportedOperationException because the collection is read-only.
int	size() This method delegates to the result collection method.
java.lang.Object[]	toArray() This method delegates to the result collection method.
java.lang.Object[]	toArray(java.lang.Object[] obj) This method delegates to the result collection method.

Methods inherited from class java.lang.Object

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

Constructor Detail

BasicQueryResult

public BasicQueryResult(QueryResultHelper qrh)

Creates new BasicQueryResult

Parameters:

qrh - the query result helper provided by the query parser.

Method Detail

close

public void close()

This method closes the result set, closes all open iterators, and releases all resources that might be held by the result.

Specified by:

close in interface QueryResult

retainAll

public boolean retainAll(java.util.Collection collection)

This method throws UnsupportedOperationException because the collection is read-only.

Specified by:

retainAll in interface java.util.Collection

Parameters:

collection - ignored.

Returns:

never.

contains

public boolean contains(java.lang.Object obj)

This method delegates to the result collection method.

Specified by:

contains in interface java.util.Collection

Parameters:

obj - the object to be tested.

Returns:

true if the result collection contains the parameter object.

toArray

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

This method delegates to the result collection method.

Specified by:

toArray in interface java.util.Collection

Parameters:

obj - an array into which to place the objects from the result collection.

Returns:

an array of all objects in the result collection that are of the runtime type of the parameter array.

iterator

public java.util.Iterator iterator()

This method delegates to the result collection method.

Specified by:

iterator in interface java.lang.Iterable

Specified by:

iterator in interface java.util.Collection

Returns:

an iterator over the result collection.

toArray

public java.lang.Object[] toArray()

This method delegates to the result collection method.

Specified by:

toArray in interface java.util.Collection

Returns:

the result collection as an array.

removeAll

public boolean removeAll(java.util.Collection collection)

This method throws UnsupportedOperationException because the collection is read-only.

Specified by:

removeAll in interface java.util.Collection

Parameters:

collection - ignored.

Returns:

never.

remove

public boolean remove(java.lang.Object obj)

This method throws UnsupportedOperationException because the collection is read-only.

Specified by:

remove in interface java.util.Collection

Parameters:

obj - ignored.

Returns:

never.

clear

public void clear()

This method throws UnsupportedOperationException because the collection is read-only.

Specified by:

clear in interface java.util.Collection

addAll

public boolean addAll(java.util.Collection collection)

This method throws UnsupportedOperationException because the collection is read-only.

Specified by:

addAll in interface java.util.Collection

Parameters:

collection - ignored.

Returns:

never.

size

public int size()

This method delegates to the result collection method.

Specified by:

size in interface java.util.Collection

Returns:

the size of the results.

containsAll

public boolean containsAll(java.util.Collection collection)

This method delegates to the result collection method.

Specified by:

containsAll in interface java.util.Collection

Parameters:

collection - a collection of elements to be tested.

Returns:

true if the result collection contains all of the elements in the parameter collection.

add

public boolean add(java.lang.Object obj)

This method throws UnsupportedOperationException because the collection is read-only.

Specified by:

add in interface java.util.Collection

Parameters:

obj - ignored.

Returns:

never.

isEmpty

public boolean isEmpty()

This method delegates to the result collection method.

Specified by:

isEmpty in interface java.util.Collection

Returns:

true if the result collection is empty.

equals

public boolean equals(java.lang.Object obj)

This method delegates to the result collection method.

Specified by:

equals in interface java.util.Collection

Overrides:

equals in class java.lang.Object

Parameters:

obj - the object to which to compare this object.

Returns:

true if the result collection is equal to the parameter collection.

hashCode

public int hashCode()

This method delegates to the result collection method.

Specified by:

hashCode in interface java.util.Collection

Overrides:

hashCode in class java.lang.Object

Returns:

the hashCode of the result collection.