/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
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package com.sun.el.lang;

import java.lang.reflect.Method;

import javax.el.FunctionMapper;

/**
 * @author Jacob Hookom [jacob@hookom.net]
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: tcfujii $
 */
public class FunctionMapperFactory extends FunctionMapper {

    protected FunctionMapperImpl memento = null;
    protected FunctionMapper target;
    
    public FunctionMapperFactory(FunctionMapper mapper) {
        if (mapper == null) {
            throw new NullPointerException("FunctionMapper target cannot be null");
        }
        this.target = mapper;
    }
   
    
    /* (non-Javadoc)
     * @see javax.el.FunctionMapper#resolveFunction(java.lang.String, java.lang.String)
     */
    public Method resolveFunction(String prefix, String localName) {
        if (this.memento == null) {
            this.memento = new FunctionMapperImpl();
        }
        Method m = this.target.resolveFunction(prefix, localName);
        if (m != null) {
            this.memento.addFunction(prefix, localName, m);
        }
        return m;
    }
    
    public FunctionMapper create() {
        return this.memento;
    }

}