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/**
*
*/
package com.xdev.jadoth.cql;
/*-
* #%L
* XDEV Application Framework
* %%
* Copyright (C) 2003 - 2020 XDEV Software
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
import com.xdev.jadoth.collections.Collecting;
import com.xdev.jadoth.collections.GrowList;
/**
* @author Thomas Muenz
*
*/
public interface CqlProjector>
{
/**
* Takes a {@link Collecting} instance that contains all entries selected by a CQL query and applies an arbitrary
* projection to all entries, returning whatever type the projector defines as the projection type
* (which is the collection containing the data itself in the simple case).
*
* In order to know the exact type of the {@link Collecting} instance to work with, the projector has to provide
* the collecting instance itself.
*
* @param selectedData
* @return the data selected by the SQL query, projected to the final result type.
*/
public P project(C selectedData);
/**
* Provides the {@link Collecting} instance that will be used by the SQL query to collect all selected entries
* and that will be passed back to the projector for projection.
*
* @return the {@link Collecting} instance to be used to collect all selected entries.
*/
public C provideCollector();
/**
* Default implementation of {@link CqlQueryHelper} which does no projection at all but returns the list containing
* the selected entries directly.
*
* @author Thomas Muenz
*
* @param
*/
public class Implementation implements CqlProjector, GrowList>
{
///////////////////////////////////////////////////////////////////////////
// instance fields //
/////////////////////
private int initialCapacity = 0;
///////////////////////////////////////////////////////////////////////////
// constructors //
/////////////////////
public Implementation(final int initialCapacity)
{
super();
this.initialCapacity = initialCapacity;
}
///////////////////////////////////////////////////////////////////////////
// getters //
/////////////////////
public int getInitialCapacity()
{
return initialCapacity;
}
///////////////////////////////////////////////////////////////////////////
// setters //
/////////////////////
public void setInitialCapacity(final int initialCapacity)
{
this.initialCapacity = initialCapacity;
}
///////////////////////////////////////////////////////////////////////////
// override methods //
/////////////////////
/**
* @return
* @see net.jadoth.cql.CqlQueryHelper#provideCollector()
*/
@Override
public GrowList provideCollector()
{
return new GrowList(this.initialCapacity);
}
/**
* @param data
* @return
* @see com.xdev.jadoth.cql.CqlProjector#project(com.xdev.jadoth.collections.XGettingCollection)
*/
@Override
public GrowList project(final GrowList data)
{
// as provider methods provides a collection of this type, casting to this type again is safe.
return data;
}
}
}