FileDocCategorySizeDatePackage
VariableResolverImpl.javaAPI DocGlassfish v2 API3388Fri May 04 22:32:54 BST 2007org.apache.jasper.runtime

VariableResolverImpl.java

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * Portions Copyright Apache Software Foundation.
 * 
 * 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
 * identifying information: "Portions Copyrighted [year]
 * [name of copyright owner]"
 * 
 * Contributor(s):
 * 
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package org.apache.jasper.runtime;

import javax.el.ELContext;
import javax.el.ELResolver;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.el.VariableResolver;


/**
 * <p>This is the implementation of VariableResolver in JSP 2.0,
 * using ELResolver in JSP2.1.
 * It looks up variable references in the PageContext, and also
 * recognizes references to implicit objects.
 * 
 * @author Kin-man Chung
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: tcfujii $
 **/

public class VariableResolverImpl
    implements VariableResolver
{
    private PageContext pageContext;

    //-------------------------------------
    /**
     * Constructor
     **/
    public VariableResolverImpl (PageContext pageContext) {
        this.pageContext = pageContext;
    }
  
    //-------------------------------------
    /**
     * Resolves the specified variable within the given context.
     * Returns null if the variable is not found.
     **/
    public Object resolveVariable (String pName)
            throws javax.servlet.jsp.el.ELException {

        ELContext elContext = pageContext.getELContext();
        ELResolver elResolver = elContext.getELResolver();
        try {
            return elResolver.getValue(elContext, null, pName);
        } catch (javax.el.ELException ex) {
            throw new javax.servlet.jsp.el.ELException();
        }
    }
}