/*
* 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 org.apache.jasper.runtime;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.el.ArrayELResolver;
import javax.el.BeanELResolver;
import javax.el.CompositeELResolver;
import javax.el.ELContextEvent;
import javax.el.ELContextListener;
import javax.el.ELResolver;
import javax.el.ExpressionFactory;
import javax.el.ListELResolver;
import javax.el.MapELResolver;
import javax.el.ResourceBundleELResolver;
import javax.servlet.ServletContext;
import javax.servlet.jsp.JspApplicationContext;
import javax.servlet.jsp.JspContext;
import javax.servlet.jsp.el.ImplicitObjectELResolver;
import javax.servlet.jsp.el.ScopedAttributeELResolver;
import org.apache.jasper.Constants;
import org.apache.jasper.el.ELContextImpl;
/**
* Implementation of JspApplicationContext
*
* @author Jacob Hookom
*/
public class JspApplicationContextImpl implements JspApplicationContext {
private final static String KEY = JspApplicationContextImpl.class.getName();
private final static ExpressionFactory expressionFactory =
ExpressionFactory.newInstance();
private final List<ELContextListener> contextListeners = new ArrayList<ELContextListener>();
private final List<ELResolver> resolvers = new ArrayList<ELResolver>();
private boolean instantiated = false;
private ELResolver resolver;
public JspApplicationContextImpl() {
}
public void addELContextListener(ELContextListener listener) {
if (listener == null) {
throw new IllegalArgumentException("ELConextListener was null");
}
this.contextListeners.add(listener);
}
public static JspApplicationContextImpl getInstance(ServletContext context) {
if (context == null) {
throw new IllegalArgumentException("ServletContext was null");
}
JspApplicationContextImpl impl = (JspApplicationContextImpl) context
.getAttribute(KEY);
if (impl == null) {
impl = new JspApplicationContextImpl();
context.setAttribute(KEY, impl);
}
return impl;
}
public ELContextImpl createELContext(JspContext context) {
if (context == null) {
throw new IllegalArgumentException("JspContext was null");
}
// create ELContext for JspContext
final ELResolver r = this.createELResolver();
ELContextImpl ctx;
if (Constants.IS_SECURITY_ENABLED) {
ctx = AccessController.doPrivileged(
new PrivilegedAction<ELContextImpl>() {
public ELContextImpl run() {
return new ELContextImpl(r);
}
});
} else {
ctx = new ELContextImpl(r);
}
ctx.putContext(JspContext.class, context);
// alert all ELContextListeners
ELContextEvent event = new ELContextEvent(ctx);
for (int i = 0; i < this.contextListeners.size(); i++) {
this.contextListeners.get(i).contextCreated(event);
}
return ctx;
}
private ELResolver createELResolver() {
this.instantiated = true;
if (this.resolver == null) {
CompositeELResolver r = new CompositeELResolver();
r.add(new ImplicitObjectELResolver());
for (Iterator itr = this.resolvers.iterator(); itr.hasNext();) {
r.add((ELResolver) itr.next());
}
r.add(new MapELResolver());
r.add(new ResourceBundleELResolver());
r.add(new ListELResolver());
r.add(new ArrayELResolver());
r.add(new BeanELResolver());
r.add(new ScopedAttributeELResolver());
this.resolver = r;
}
return this.resolver;
}
public void addELResolver(ELResolver resolver) throws IllegalStateException {
if (resolver == null) {
throw new IllegalArgumentException("ELResolver was null");
}
if (this.instantiated) {
throw new IllegalStateException(
"cannot call addELResolver after the first request has been made");
}
this.resolvers.add(resolver);
}
public ExpressionFactory getExpressionFactory() {
return expressionFactory;
}
}