/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This 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 2.1 of
* the License, or (at your option) any later version.
*
* This software 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 software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.deployment.scanner;
import java.util.Comparator;
import java.net.URL;
import org.jboss.deployment.DeploymentSorter;
import org.jboss.deployment.DefaultDeploymentSorter;
/**
* <p>This class is a comparator to sort deployment URLs based on the existence
* of a numeric prefix. The name portion of the URL is evaluated for any
* leading digits. If they exist, then they will define a numerical ordering
* for this comparator. If there is no leading digits, then they will
* compare as less than any name with leading digits. In the case of a
* tie, the DeploymentSorter is consulted (@see org.jboss.deployment.DeploymentSorter).
*
* <p>Ex.these names are in ascending order:
* test.sar, crap.ear, 001test.jar, 5test.rar, 5foo.jar, 120bar.jar
*/
public class PrefixDeploymentSorter implements Comparator, DefaultDeploymentSorter
{
/** This is used to break ties */
private DeploymentSorter sorter = new DeploymentSorter();
public String[] getSuffixOrder()
{
return sorter.getSuffixOrder();
}
public void setSuffixOrder(String[] suffixOrder)
{
sorter.setSuffixOrder(suffixOrder);
}
/**
* As described in @see java.util.Comparator. This implements the
* comparison technique described above.
*/
public int compare(Object o1, Object o2) {
int comp = getPrefixValue((URL)o1) - getPrefixValue((URL)o2);
return comp == 0 ? sorter.compare(o1, o2) : comp;
}
/**
* This extracts the prefix value from the name of a URL. If no prefix
* value exists, this returns -1
*/
private int getPrefixValue(URL url) {
String path = url.getPath();
int nameEnd = path.length() - 1;
if (nameEnd <= 0) {
return 0;
}
// ignore a trailing '/'
if (path.charAt(nameEnd) == '/') {
nameEnd--;
}
// find the previous URL separator: '/'
int nameStart = path.lastIndexOf('/', nameEnd) + 1;
// calculate where the digit-prefix ends
int prefixEnd = nameStart;
while (prefixEnd <= nameEnd && Character.isDigit(path.charAt(prefixEnd))) {
prefixEnd++;
}
// If zero length prefix, return -1
if (prefixEnd == nameStart) {
return -1;
}
// strip leading zeroes
while (nameStart < prefixEnd && path.charAt(nameStart) == '0') {
nameStart++;
}
return (nameStart == prefixEnd) ? 0 : Integer.parseInt(path.substring(nameStart, prefixEnd));
}
}