/*
* Copyright 2002-2014 the original author or authors.
*
* 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 org.springframework.web.jsf;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.util.WebUtils;
Convenience methods to retrieve Spring's root WebApplicationContext for a given JSF FacesContext. This is useful for accessing a Spring application context from custom JSF-based code. Analogous to Spring's WebApplicationContextUtils for the ServletContext.
Author: Juergen Hoeller See Also: Since: 1.1
/**
* Convenience methods to retrieve Spring's root {@link WebApplicationContext}
* for a given JSF {@link FacesContext}. This is useful for accessing a
* Spring application context from custom JSF-based code.
*
* <p>Analogous to Spring's WebApplicationContextUtils for the ServletContext.
*
* @author Juergen Hoeller
* @since 1.1
* @see org.springframework.web.context.ContextLoader
* @see org.springframework.web.context.support.WebApplicationContextUtils
*/
public abstract class FacesContextUtils {
Find the root WebApplicationContext for this web app, typically loaded via ContextLoaderListener. Will rethrow an exception that happened on root context startup,
to differentiate between a failed context startup and no context at all.
Params: - fc – the FacesContext to find the web application context for
See Also: Returns: the root WebApplicationContext for this web app, or null if none
/**
* Find the root {@link WebApplicationContext} for this web app, typically
* loaded via {@link org.springframework.web.context.ContextLoaderListener}.
* <p>Will rethrow an exception that happened on root context startup,
* to differentiate between a failed context startup and no context at all.
* @param fc the FacesContext to find the web application context for
* @return the root WebApplicationContext for this web app, or {@code null} if none
* @see org.springframework.web.context.WebApplicationContext#ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE
*/
@Nullable
public static WebApplicationContext getWebApplicationContext(FacesContext fc) {
Assert.notNull(fc, "FacesContext must not be null");
Object attr = fc.getExternalContext().getApplicationMap().get(
WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
if (attr == null) {
return null;
}
if (attr instanceof RuntimeException) {
throw (RuntimeException) attr;
}
if (attr instanceof Error) {
throw (Error) attr;
}
if (!(attr instanceof WebApplicationContext)) {
throw new IllegalStateException("Root context attribute is not of type WebApplicationContext: " + attr);
}
return (WebApplicationContext) attr;
}
Find the root WebApplicationContext for this web app, typically loaded via ContextLoaderListener. Will rethrow an exception that happened on root context startup,
to differentiate between a failed context startup and no context at all.
Params: - fc – the FacesContext to find the web application context for
Throws: - IllegalStateException – if the root WebApplicationContext could not be found
See Also: Returns: the root WebApplicationContext for this web app
/**
* Find the root {@link WebApplicationContext} for this web app, typically
* loaded via {@link org.springframework.web.context.ContextLoaderListener}.
* <p>Will rethrow an exception that happened on root context startup,
* to differentiate between a failed context startup and no context at all.
* @param fc the FacesContext to find the web application context for
* @return the root WebApplicationContext for this web app
* @throws IllegalStateException if the root WebApplicationContext could not be found
* @see org.springframework.web.context.WebApplicationContext#ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE
*/
public static WebApplicationContext getRequiredWebApplicationContext(FacesContext fc) throws IllegalStateException {
WebApplicationContext wac = getWebApplicationContext(fc);
if (wac == null) {
throw new IllegalStateException("No WebApplicationContext found: no ContextLoaderListener registered?");
}
return wac;
}
Return the best available mutex for the given session:
that is, an object to synchronize on for the given session.
Returns the session mutex attribute if available; usually, this means that the HttpSessionMutexListener needs to be defined in web.xml. Falls back to the Session reference itself if no mutex attribute found.
The session mutex is guaranteed to be the same object during the entire lifetime of the session, available under the key defined by the SESSION_MUTEX_ATTRIBUTE constant. It serves as a safe reference to synchronize on for locking on the current session.
In many cases, the Session reference itself is a safe mutex
as well, since it will always be the same object reference for the
same active logical session. However, this is not guaranteed across
different servlet containers; the only 100% safe way is a session mutex.
Params: - fc – the FacesContext to find the session mutex for
See Also: Returns: the mutex object (never null)
/**
* Return the best available mutex for the given session:
* that is, an object to synchronize on for the given session.
* <p>Returns the session mutex attribute if available; usually,
* this means that the HttpSessionMutexListener needs to be defined
* in {@code web.xml}. Falls back to the Session reference itself
* if no mutex attribute found.
* <p>The session mutex is guaranteed to be the same object during
* the entire lifetime of the session, available under the key defined
* by the {@code SESSION_MUTEX_ATTRIBUTE} constant. It serves as a
* safe reference to synchronize on for locking on the current session.
* <p>In many cases, the Session reference itself is a safe mutex
* as well, since it will always be the same object reference for the
* same active logical session. However, this is not guaranteed across
* different servlet containers; the only 100% safe way is a session mutex.
* @param fc the FacesContext to find the session mutex for
* @return the mutex object (never {@code null})
* @see org.springframework.web.util.WebUtils#SESSION_MUTEX_ATTRIBUTE
* @see org.springframework.web.util.HttpSessionMutexListener
*/
@Nullable
public static Object getSessionMutex(FacesContext fc) {
Assert.notNull(fc, "FacesContext must not be null");
ExternalContext ec = fc.getExternalContext();
Object mutex = ec.getSessionMap().get(WebUtils.SESSION_MUTEX_ATTRIBUTE);
if (mutex == null) {
mutex = ec.getSession(true);
}
return mutex;
}
}