org.simpleframework.xml.core.Revision Maven / Gradle / Ivy
/*
* Revision.java July 2008
*
* Copyright (C) 2008, Niall Gallagher
*
* This library 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.
*
* This library 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*/
package org.simpleframework.xml.core;
/**
* The Revision object is used represent the revision
* of a class as read from a version attribute. It determines the
* type of deserialization that takes place.
*
* @author Niall Gallagher
*/
class Revision {
/**
* This is used to track the revision comparision of the class.
*/
private boolean equal;
/**
* Constructor of the Revision object. This is used
* to create a comparator object that will compare and cache the
* comparison of the expected and current version of the class.
*/
public Revision() {
this.equal = true;
}
/**
* This is used to acquire the default revision. The default
* revision is the revision expected if there is not attribute
* representing the version in the XML element for the object.
*
* @return this returns the default version for the object
*/
public double getDefault() {
return 1.0;
}
/**
* This is used to compare the expected and current versions of
* the class. Once compared the comparison result is cached
* within the revision class so that it can be used repeatedly.
*
* @param expected this is the expected version of the class
* @param current this is the current version of the class
*
* @return this returns true if the versions are the same
*/
public boolean compare(Object expected, Object current) {
if(current != null) {
equal = current.equals(expected);
} else if(expected != null) {
equal = expected.equals(1.0);
}
return equal;
}
/**
* This returns the cached comparision of the revisions. This
* will be true if not comparison was performed. If however one
* was performed then this will represent the result.
*
* @return this returns the cached version of the comparison
*/
public boolean isEqual() {
return equal;
}
}