/*
 * 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 jakarta.servlet.jsp.el;

import java.beans.FeatureDescriptor;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;

import jakarta.el.ELClass;
import jakarta.el.ELContext;
import jakarta.el.ELResolver;
import jakarta.el.ImportHandler;
import jakarta.servlet.jsp.JspContext;
import jakarta.servlet.jsp.PageContext;

Since:2.1
/** * * @since 2.1 */
public class ScopedAttributeELResolver extends ELResolver { // Indicates if a performance short-cut is available private static final Class<?> AST_IDENTIFIER_KEY; static { Class<?> key = null; try { key = Class.forName("org.apache.el.parser.AstIdentifier"); } catch (Exception e) { // Ignore: Expected if not running on Tomcat. Not a problem since // this just allows a short-cut. } AST_IDENTIFIER_KEY = key; } @Override public Object getValue(ELContext context, Object base, Object property) { Objects.requireNonNull(context); Object result = null; if (base == null) { context.setPropertyResolved(base, property); if (property != null) { String key = property.toString(); PageContext page = (PageContext) context.getContext(JspContext.class); result = page.findAttribute(key); if (result == null) { boolean resolveClass = true; // Performance short-cut available when running on Tomcat if (AST_IDENTIFIER_KEY != null) { // Tomcat will set this key to Boolean.TRUE if the // identifier is a stand-alone identifier (i.e. // identifier) rather than part of an AstValue (i.e. // identifier.something). Imports do not need to be // checked if this is a stand-alone identifier Boolean value = (Boolean) context.getContext(AST_IDENTIFIER_KEY); if (value != null && value.booleanValue()) { resolveClass = false; } } // This might be the name of an imported class ImportHandler importHandler = context.getImportHandler(); if (importHandler != null) { Class<?> clazz = null; if (resolveClass) { clazz = importHandler.resolveClass(key); } if (clazz != null) { result = new ELClass(clazz); } if (result == null) { // This might be the name of an imported static field clazz = importHandler.resolveStatic(key); if (clazz != null) { try { result = clazz.getField(key).get(null); } catch (IllegalArgumentException | IllegalAccessException | NoSuchFieldException | SecurityException e) { // Most (all?) of these should have been // prevented by the checks when the import // was defined. } } } } } } } return result; } @Override public Class<Object> getType(ELContext context, Object base, Object property) { Objects.requireNonNull(context); if (base == null) { context.setPropertyResolved(base, property); return Object.class; } return null; } @Override public void setValue(ELContext context, Object base, Object property, Object value) { Objects.requireNonNull(context); if (base == null) { context.setPropertyResolved(base, property); if (property != null) { String key = property.toString(); PageContext page = (PageContext) context.getContext(JspContext.class); int scope = page.getAttributesScope(key); if (scope != 0) { page.setAttribute(key, value, scope); } else { page.setAttribute(key, value); } } } } @Override public boolean isReadOnly(ELContext context, Object base, Object property) { Objects.requireNonNull(context); if (base == null) { context.setPropertyResolved(base, property); } return false; } @Override public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base) { PageContext ctxt = (PageContext) context.getContext(JspContext.class); List<FeatureDescriptor> list = new ArrayList<>(); Enumeration<String> e; Object value; String name; e = ctxt.getAttributeNamesInScope(PageContext.PAGE_SCOPE); while (e.hasMoreElements()) { name = e.nextElement(); value = ctxt.getAttribute(name, PageContext.PAGE_SCOPE); FeatureDescriptor descriptor = new FeatureDescriptor(); descriptor.setName(name); descriptor.setDisplayName(name); descriptor.setExpert(false); descriptor.setHidden(false); descriptor.setPreferred(true); descriptor.setShortDescription("page scoped attribute"); descriptor.setValue("type", value.getClass()); descriptor.setValue("resolvableAtDesignTime", Boolean.FALSE); list.add(descriptor); } e = ctxt.getAttributeNamesInScope(PageContext.REQUEST_SCOPE); while (e.hasMoreElements()) { name = e.nextElement(); value = ctxt.getAttribute(name, PageContext.REQUEST_SCOPE); FeatureDescriptor descriptor = new FeatureDescriptor(); descriptor.setName(name); descriptor.setDisplayName(name); descriptor.setExpert(false); descriptor.setHidden(false); descriptor.setPreferred(true); descriptor.setShortDescription("request scope attribute"); descriptor.setValue("type", value.getClass()); descriptor.setValue("resolvableAtDesignTime", Boolean.FALSE); list.add(descriptor); } if (ctxt.getSession() != null) { e = ctxt.getAttributeNamesInScope(PageContext.SESSION_SCOPE); while (e.hasMoreElements()) { name = e.nextElement(); value = ctxt.getAttribute(name, PageContext.SESSION_SCOPE); FeatureDescriptor descriptor = new FeatureDescriptor(); descriptor.setName(name); descriptor.setDisplayName(name); descriptor.setExpert(false); descriptor.setHidden(false); descriptor.setPreferred(true); descriptor.setShortDescription("session scoped attribute"); descriptor.setValue("type", value.getClass()); descriptor.setValue("resolvableAtDesignTime", Boolean.FALSE); list.add(descriptor); } } e = ctxt.getAttributeNamesInScope(PageContext.APPLICATION_SCOPE); while (e.hasMoreElements()) { name = e.nextElement(); value = ctxt.getAttribute(name, PageContext.APPLICATION_SCOPE); FeatureDescriptor descriptor = new FeatureDescriptor(); descriptor.setName(name); descriptor.setDisplayName(name); descriptor.setExpert(false); descriptor.setHidden(false); descriptor.setPreferred(true); descriptor.setShortDescription("application scoped attribute"); descriptor.setValue("type", value.getClass()); descriptor.setValue("resolvableAtDesignTime", Boolean.FALSE); list.add(descriptor); } return list.iterator(); } @Override public Class<String> getCommonPropertyType(ELContext context, Object base) { if (base == null) { return String.class; } return null; } }