/*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2002 The Apache Software Foundation. All rights
* reserved.
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* are met:
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* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
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* ====================================================================
*
* This software consists of voluntary contributions made by many
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package org.apache.commons.discovery.resource.names;
import java.util.Vector;
import org.apache.commons.discovery.ResourceNameDiscover;
import org.apache.commons.discovery.ResourceNameIterator;
import org.apache.commons.discovery.log.DiscoveryLogFactory;
import org.apache.commons.logging.Log;
/**
* Holder for multiple ResourceNameDiscover instances.
* The result is the union of the results from each
* (not a chained sequence, where results feed the next in line.
*
* @author Richard A. Sitze
*/
public class NameDiscoverers
extends ResourceNameDiscoverImpl
implements ResourceNameDiscover
{
private static Log log = DiscoveryLogFactory.newLog(NameDiscoverers.class);
public static void setLog(Log _log) {
log = _log;
}
private Vector discoverers = new Vector();
/**
* Construct a new resource name discoverer
*/
public NameDiscoverers() {
}
/**
* Specify an additional class loader to be used in searching.
* The order of loaders determines the order of the result.
* It is recommended to add the most specific loaders first.
*/
public void addResourceNameDiscover(ResourceNameDiscover discover) {
if (discover != null) {
discoverers.addElement(discover);
}
}
protected ResourceNameDiscover getResourceNameDiscover(int idx) {
return (ResourceNameDiscover)discoverers.get(idx);
}
protected int size() {
return discoverers.size();
}
/**
* Set of results of all discoverers.
*
* @return ResourceIterator
*/
public ResourceNameIterator findResourceNames(final String resourceName) {
if (log.isDebugEnabled())
log.debug("find: resourceName='" + resourceName + "'");
return new ResourceNameIterator() {
private int idx = 0;
private ResourceNameIterator iterator = null;
public boolean hasNext() {
if (iterator == null || !iterator.hasNext()) {
iterator = getNextIterator();
if (iterator == null) {
return false;
}
}
return iterator.hasNext();
}
public String nextResourceName() {
return iterator.nextResourceName();
}
private ResourceNameIterator getNextIterator() {
while (idx < size()) {
ResourceNameIterator iter =
getResourceNameDiscover(idx++).findResourceNames(resourceName);
if (iter.hasNext()) {
return iter;
}
}
return null;
}
};
}
}