/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jackrabbit.core.version;
import javax.jcr.RepositoryException;
import javax.jcr.version.Version;
import javax.jcr.version.VersionHistory;
import javax.jcr.version.VersionIterator;
import java.util.Calendar;
/**
* This Class implements a version selector that selects a version by creation
* date. The selected version is the latest that is older or equal than the
* given date. If no version could be found <code>null</code> is returned
* unless the <code>returnLatest</code> flag is set to <code>true</code>, where
* the latest version is returned.
* <xmp>
* V1.0 - 02-Sep-2006
* V1.1 - 03-Sep-2006
* V1.2 - 05-Sep-2006
*
* new DateVersionSelector("03-Sep-2006").select() -> V1.1
* new DateVersionSelector("04-Sep-2006").select() -> V1.1
* new DateVersionSelector("01-Sep-2006").select() -> null
* new DateVersionSelector("01-Sep-2006", true).select() -> V1.2
* new DateVersionSelector(null, true).select() -> V1.2
* </xmp>
*/
public class DateVersionSelector implements VersionSelector {
/**
* a version date hint
*/
private Calendar date = null;
/**
* flag indicating that it should return the latest version, if no other
* found
*/
private boolean returnLatest = false;
/**
* Creates a <code>DateVersionSelector</code> that will select the latest
* version of all those that are older than the given date.
*
* @param date
*/
public DateVersionSelector(Calendar date) {
this.date = date;
}
/**
* Creates a <code>DateVersionSelector</code> that will select the latest
* version of all those that are older than the given date.
*
* @param date
* @param returnLatest
*/
public DateVersionSelector(Calendar date, boolean returnLatest) {
this.date = date;
this.returnLatest = returnLatest;
}
/**
* Returns the date hint
*
* @return the date hint.
*/
public Calendar getDate() {
return date;
}
/**
* Sets the date hint
*
* @param date
*/
public void setDate(Calendar date) {
this.date = date;
}
/**
* Returns the flag, if the latest version should be selected, if no
* version can be found using the given hint.
*
* @return <code>true</code> if it returns latest.
*/
public boolean isReturnLatest() {
return returnLatest;
}
/**
* Sets the flag, if the latest version should be selected, if no
* version can be found using the given hint.
*
* @param returnLatest
*/
public void setReturnLatest(boolean returnLatest) {
this.returnLatest = returnLatest;
}
/**
* Selects a version from the given version history using the previously
* assigned hint in the following order: name, label, date, latest.
*
* @param versionHistory
* @return
* @throws RepositoryException
*/
public Version select(VersionHistory versionHistory) throws RepositoryException {
Version selected = null;
if (date != null) {
selected = DateVersionSelector.selectByDate(versionHistory, date);
}
if (selected == null && returnLatest) {
selected = DateVersionSelector.selectByDate(versionHistory, null);
}
return selected;
}
/**
* Selects a version by date.
*
* @param history
* @param date
* @return the latest version that is older than the given date date or
* <code>null</code>
* @throws RepositoryException
*/
public static Version selectByDate(VersionHistory history, Calendar date)
throws RepositoryException {
long time = (date != null) ? date.getTimeInMillis() : Long.MAX_VALUE;
long latestDate = Long.MIN_VALUE;
Version latestVersion = null;
VersionIterator iter = history.getAllVersions();
while (iter.hasNext()) {
Version v = iter.nextVersion();
if (v.getPredecessors().length == 0) {
// ignore root version
continue;
}
long c = v.getCreated().getTimeInMillis();
if (c > latestDate && c <= time) {
latestDate = c;
latestVersion = v;
}
}
return latestVersion;
}
/**
* returns debug information
* @return debug information
*/
public String toString() {
StringBuffer ret = new StringBuffer();
ret.append("DateVersionSelector(");
ret.append("date=");
ret.append(date);
ret.append(", returnLatest=");
ret.append(returnLatest);
ret.append(")");
return ret.toString();
}
}