/*
* 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.myfaces.el;
import java.beans.FeatureDescriptor;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.NoSuchElementException;
import javax.el.ELContext;
import javax.el.ELResolver;
/**
* @author Mathias Broekelmann (latest modification by $Author: bommel $)
* @version $Revision: 693059 $ $Date: 2008-09-08 07:42:28 -0400 (Mon, 08 Sep 2008) $
*/
public class CompositeELResolver extends javax.el.CompositeELResolver
{
private Collection<ELResolver> _elResolvers = Collections.EMPTY_LIST;
@Override
public Iterator<FeatureDescriptor> getFeatureDescriptors(final ELContext context, final Object base)
{
return new CompositeIterator(context, base, _elResolvers.iterator());
}
/**
* @param elResolver
*/
public final void add(final ELResolver elResolver)
{
super.add(elResolver);
if (_elResolvers == Collections.EMPTY_LIST)
{
_elResolvers = new ArrayList();
}
_elResolvers.add(elResolver);
}
private static class CompositeIterator implements Iterator<FeatureDescriptor>
{
private final ELContext _context;
private final Object _base;
private final Iterator<ELResolver> _elResolvers;
private FeatureDescriptor _nextFD;
private Iterator<FeatureDescriptor> _currentFDIter;
public CompositeIterator(final ELContext context, final Object base, final Iterator<ELResolver> elResolvers)
{
_context = context;
_base = base;
_elResolvers = elResolvers;
}
public boolean hasNext()
{
if (_nextFD != null)
return true;
if (_currentFDIter != null)
{
while (_nextFD == null && _currentFDIter.hasNext())
{
_nextFD = _currentFDIter.next();
}
}
if (_nextFD == null)
{
if (_elResolvers.hasNext())
{
_currentFDIter = _elResolvers.next().getFeatureDescriptors(_context, _base);
}
else
{
return false;
}
}
return hasNext();
}
public FeatureDescriptor next()
{
if (!hasNext())
throw new NoSuchElementException();
FeatureDescriptor next = _nextFD;
_nextFD = null;
return next;
}
public void remove()
{
throw new UnsupportedOperationException();
}
}
}