001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software, please see the
018 * company website: https://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: https://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.jsp.util;
029
030import jakarta.el.ELContext;
031import jakarta.servlet.jsp.el.ScopedAttributeELResolver;
032
033/**
034 * Does basically the same as ScopedAttributeELResolver, but always marks top-level properties as resolved
035 * even if no value was found.
036 * <p>This is meant to bypass ImportELResolver (in Jakarta EE 10 and later), which comes later in the resolver chain and would be normally triggered later for an unresolved
037 * property, but incurs a heavy performance penalty on Jetty, especially in combination with the Mercury template,
038 * where potentially undefined top-level variables are used a lot.
039 * <p>Using this means that the functionality provided by ImportELResolver will not be available in OpenCms JSPs.
040 */
041public class CmsJspSimpleELResolver extends ScopedAttributeELResolver {
042
043    /**
044     * @see jakarta.servlet.jsp.el.ScopedAttributeELResolver#getCommonPropertyType(jakarta.el.ELContext, java.lang.Object)
045     */
046    @Override
047    public Class<String> getCommonPropertyType(ELContext context, Object base) {
048
049        return super.getCommonPropertyType(context, base);
050
051    }
052
053    /**
054     * @see jakarta.servlet.jsp.el.ScopedAttributeELResolver#getType(jakarta.el.ELContext, java.lang.Object, java.lang.Object)
055     */
056    @Override
057    public Class<Object> getType(ELContext context, Object base, Object property) {
058
059        if (base == null) {
060            Class<Object> result = super.getType(context, base, property);
061            context.setPropertyResolved(true);
062            return result;
063        }
064        return null;
065
066    }
067
068    /**
069     * @see jakarta.servlet.jsp.el.ScopedAttributeELResolver#getValue(jakarta.el.ELContext, java.lang.Object, java.lang.Object)
070     */
071    @Override
072    public Object getValue(ELContext context, Object base, Object property) {
073
074        if (base == null) {
075            Object result = super.getValue(context, base, property);
076            context.setPropertyResolved(true);
077            return result;
078        }
079        return null;
080    }
081
082    /**
083     * @see jakarta.servlet.jsp.el.ScopedAttributeELResolver#isReadOnly(jakarta.el.ELContext, java.lang.Object, java.lang.Object)
084     */
085    @Override
086    public boolean isReadOnly(ELContext context, Object base, Object property) {
087
088        if (base == null) {
089            boolean result = super.isReadOnly(context, base, property);
090            context.setPropertyResolved(true);
091            return result;
092        }
093        return false;
094    }
095
096    /**
097     * @see jakarta.servlet.jsp.el.ScopedAttributeELResolver#setValue(jakarta.el.ELContext, java.lang.Object, java.lang.Object, java.lang.Object)
098     */
099    @Override
100    public void setValue(ELContext context, Object base, Object property, Object value) {
101
102        if (base == null) {
103            super.setValue(context, base, property, value);
104            context.setPropertyResolved(true);
105        }
106    }
107}