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/*******************************************************************************
 * Copyright (c) 1998, 2014 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the 
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 
 * which accompanies this distribution. 
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at 
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
 ******************************************************************************/  
package org.eclipse.persistence.sequencing;

import java.util.Vector;
import org.eclipse.persistence.internal.databaseaccess.Accessor;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.exceptions.ValidationException;
import org.eclipse.persistence.exceptions.DatabaseException;

/**
 * 

* Purpose: An abstract class providing default sequence behavior. *

*/ public abstract class StandardSequence extends Sequence { public StandardSequence() { super(); } public StandardSequence(String name) { super(name); } public StandardSequence(String name, int size) { super(name, size); } public StandardSequence(String name, int size, int initialValue) { super(name, size, initialValue); } public void onConnect() { // does nothing } public void onDisconnect() { // does nothing } protected abstract Number updateAndSelectSequence(Accessor accessor, AbstractSession writeSession, String seqName, int size); public abstract boolean shouldAcquireValueAfterInsert(); public abstract boolean shouldUseTransaction(); public Object getGeneratedValue(Accessor accessor, AbstractSession writeSession, String seqName) { if (shouldUsePreallocation()) { return null; } else { Number value = updateAndSelectSequence(accessor, writeSession, seqName, 1); if (value == null) { throw DatabaseException.errorPreallocatingSequenceNumbers(); } return value; } } public Vector getGeneratedVector(Accessor accessor, AbstractSession writeSession, String seqName, int size) { if (shouldUsePreallocation()) { Number value = updateAndSelectSequence(accessor, writeSession, seqName, size); if (value == null) { throw DatabaseException.errorPreallocatingSequenceNumbers(); } return createVector(value, seqName, size); } else { return null; } } /** * INTERNAL: * given sequence = 10, size = 5 will create Vector (6,7,8,9,10) * @param seqName String is sequencing number field name * @param size int size of Vector to create. */ protected Vector createVector(Number sequence, String seqName, int size) { long nextSequence = sequence.longValue(); Vector sequencesForName = new Vector(size); nextSequence = nextSequence - size; // Check for incorrect values return to validate that the sequence is setup correctly. // PRS 36451 intvalue would wrap if (nextSequence < -1L) { throw ValidationException.sequenceSetupIncorrectly(seqName); } for (int index = size; index > 0; index--) { nextSequence = nextSequence + 1L; sequencesForName.add(nextSequence); } return sequencesForName; } public void setInitialValue(int initialValue) { // sequence value should be positive if (initialValue <= 0) { initialValue = 1; } super.setInitialValue(initialValue); } }




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