javax.servlet.jsp.JspApplicationContext Maven / Gradle / Ivy
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2008 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
* 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.
*
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* Copyright 2004 The Apache Software Foundation
*
* Licensed 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 javax.servlet.jsp;
import javax.el.ELResolver;
import javax.el.ExpressionFactory;
import javax.el.ELContextListener;
/**
* Stores application-scoped information relevant to JSP containers.
*
* The JSP container must create a single instance of
* JspApplicationContext for each
* ServletContext instance.
*
* An instance of JspApplicationContext is obtained by
* invoking the static {@link JspFactory#getJspApplicationContext} method,
* passing the ServletContext of the corresponding web
* application.
*
* The JspApplicationContext provides the following services
* to JSP applications:
*
* - Allows registration of
ELResolvers, which are used to
* resolve variables in EL expressions contained in JSP pages and
* tag files.
* - Provides an instance of
ExpressionFactory for those
* applications or frameworks that need to perform programmatic
* evaluation of EL expressions instead of allowing the JSP
* container to do it for them.
* - Allows the attachment of
ELContextListener instances
* for notification whenever a new ELContext is created.
* This is necessary when an application wishes to make custom
* context objects available to their pluggable
* ELResolvers.
*
*
*
* @see javax.servlet.ServletContext
* @see JspFactory
* @see javax.el.ELResolver
* @see javax.el.ExpressionFactory
* @see javax.el.ELContextListener
* @since JSP 2.1
*/
public interface JspApplicationContext {
/**
* Adds an ELResolver to affect the way EL variables
* and properties are resolved for EL expressions appearing in JSP pages
* and tag files.
*
* For example, in the EL expression ${employee.lastName}, an
* ELResolver determines what object "employee"
* references and how to find its "lastName" property.
*
* When evaluating an expression, the JSP container will consult a
* set of standard resolvers as well as any resolvers registered via
* this method. The set of resolvers are consulted in the following
* order:
*
* - {@link javax.servlet.jsp.el.ImplicitObjectELResolver}
* ELResolvers registered via this method, in the
* order in which they are registered.- {@link javax.el.MapELResolver}
* - {@link javax.el.ListELResolver}
* - {@link javax.el.ArrayELResolver}
* - {@link javax.el.BeanELResolver}
* - {@link javax.servlet.jsp.el.ScopedAttributeELResolver}
*
*
* It is illegal to register an ELResolver after the
* application has received any request from the client. If an
* attempt is made to register an ELResolver after that time,
* an IllegalStateException is thrown.
* This restriction is
* in place to allow the JSP container to optimize for the common
* case where no additional ELResolvers are in the chain,
* aside from the standard ones. It is permissible to add
* ELResolvers before or after initialization to
* a CompositeELResolver that is already in the chain.
*
* It is not possible to remove an ELResolver registered
* with this method, once it has been registered.
*
* @param resolver The new ELResolver
* @throws IllegalStateException if an attempt is made to
* call this method after all ServletContextListeners
* have had their contextInitialized methods invoked.
*/
public void addELResolver(ELResolver resolver);
/**
* Returns a factory used to create ValueExpressions and
* MethodExpressions so that EL expressions can be
* parsed and evaluated.
*
* @return A concrete implementation of the
* an ExpressionFactory.
*/
public ExpressionFactory getExpressionFactory();
/**
* Registers a ELContextListeners so that context objects
* can be added whenever a new ELContext is created.
*
* At a minimum, the ELContext objects created will
* contain a reference to the JspContext for this request,
* which is added by the JSP container.
* This is sufficient for all the
* default ELResolvers listed in {@link #addELResolver}.
* Note that JspContext.class is used as the key to ELContext.putContext()
* for the JspContext object reference.
*
* This method is generally used by frameworks and applications that
* register their own ELResolver that needs context other
* than JspContext. The listener will typically add the
* necessary context to the ELContext provided in the
* event object. Registering a listener that adds context allows the
* ELResolvers in the stack to access the context they
* need when they do a resolution.
*
* @param listener The listener to be notified when a new
* ELContext is created.
*/
public void addELContextListener(ELContextListener listener);
}