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The private implementation classes of the Apache MyFaces Core JSF-2.0 Implementation
/*
* 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.myfaces.shared.util;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Method;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.faces.context.ExternalContext;
import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.ServletResponseWrapper;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.myfaces.shared.view.HttpServletResponseSwitch;
import org.apache.myfaces.shared.view.ResponseSwitch;
import org.apache.myfaces.shared.view.ServletResponseSwitch;
/**
* This provides some functionality for determining some things about the
* native request object that is not provided by the base utils.
*
* @version $Revision: 1151677 $ $Date: 2011-07-27 19:03:59 -0500 (Wed, 27 Jul 2011) $
*/
public final class ExternalContextUtils
{
/**
* Returns true if a particular class relating to the supplied
* request type is available on the current classpath or false
* if it is not. This class assumes that all containers have a servlet type
* request available, but the portlet request types are all dependant on the
* portlet container being used.
*
* @param type the RequestType to test
* @return a boolean value of true if the container contains the
* request type in the classpath
* @since 2.0
*/
public static final boolean isRequestTypeAvailable(RequestType type)
{
switch (type)
{
case SERVLET:
return true;
case ACTION:
case RENDER:
return _PORTLET_CONTEXT_CLASS != null;
case RESOURCE:
case EVENT:
return _PORTLET_RENDER_REQUEST_CLASS != null;
default:
return false;
}
}
/**
* Returns true if a particular request type is supported by the
* container. For a request type to be supported, the required objects must
* be on the classpath AND and, in the case of Portlet RequestTypes, an
* appropriate bridge must be avaialble which supports those objects. This
* means that if the supplied RequestType is RESOURCE, the
* javax.portlet.ResourceRequest object must be available on the classpath AND
* a bridge which supports the Portlet 2.0 specification would also need to be
* available.
*
* @param type the RequestType to test
* @return a boolean value of true if the container supports the
* current request type
* @since 2.0
*/
public static final boolean isRequestTypeSupported(RequestType type)
{
switch (type)
{
case SERVLET:
return true;
case ACTION:
case RENDER:
return _PORTLET_10_SUPPORTED;
case RESOURCE:
case EVENT:
return _PORTLET_20_SUPPORTED;
default:
return false;
}
}
/**
* Returns the requestType of this ExternalContext.
*
* @param ec the current external context
* @return the appropriate RequestType for this external context
* @see RequestType
* @since 2.0
*/
public static final RequestType getRequestType(ExternalContext ec)
{
// Stuff is laid out strangely in this class in order to optimize
// performance. We want to do as few instanceof's as possible so
// things are laid out according to the expected frequency of the
// various requests occurring.
if(_PORTLET_10_SUPPORTED)
{
if (_PORTLET_CONTEXT_CLASS.isInstance(ec.getContext()))
{
//We are inside of a portlet container
Object request = ec.getRequest();
if(_PORTLET_RENDER_REQUEST_CLASS.isInstance(request))
{
return RequestType.RENDER;
}
if(_PORTLET_RESOURCE_REQUEST_CLASS != null)
{
if(_PORTLET_ACTION_REQUEST_CLASS.isInstance(request))
{
return RequestType.ACTION;
}
// We are in a JSR-286 container
if(_PORTLET_RESOURCE_REQUEST_CLASS.isInstance(request))
{
return RequestType.RESOURCE;
}
return RequestType.EVENT;
}
return RequestType.ACTION;
}
}
return RequestType.SERVLET;
}
/**
* Returns the current active session id or null if there is
* none. If a session is not already created, this method will create one
* for you.
*
* @param ec the current external context
* @return a string containing the requestedSessionId
*/
public static String getSessionId(ExternalContext ec)
{
return getSessionId(ec, true);
}
/**
* Returns the current active session id or null if there is
* none.
*
* @param ec the current external context
* @param create create a new session if one is not created
* @return a string containing the requestedSessionId
*/
public static String getSessionId(ExternalContext ec, boolean create)
{
Object session = ec.getSession(create);
return (null!=session)?(String)_runMethod(session, "getId"):null;
}
/**
* Returns the session ID for the client, or null if there is none.
*
* @param ec the current external context
* @return a string containing the requestedSessionId
*/
public static String getRequestedSessionId(ExternalContext ec)
{
return (String) _runMethod(ec.getRequest(), "getRequestedSessionId");
}
/**
* Checks if the requested session ID is still valid.
*
* @param ec the current external context
* @return a boolean containing true if the request session is
* valid or false if it is not
*/
public static boolean isRequestedSessionIdValid(ExternalContext ec)
{
return (Boolean) _runMethod(ec.getRequest(), "isRequestedSessionIdValid");
}
/**
* Returns the contextPath of the ServletContext or null for portlets
*
* @param ec the current external context
* @return a String containing the servletContextPath
*/
public static String getServletContextPath(ExternalContext ec)
{
if(!isPortlet(ec))
{
return ((ServletContext) ec.getContext()).getContextPath();
}
else
{
return null;
}
}
/**
* Returns the contextPath of the ServletRequest or null for portlet requests
*
* @param ec the current external context
* @return a String containing the request context path
* @see ExternalContext#getRequestContextPath()
*
* @deprecated use ExternalContext.getRequestContextPath() as of JSF 1.2. This method
* does not appropriately handle portlet environments, but the functionality
* is maintained to prevent needing to change the contract.
*/
@Deprecated
public static String getRequestContextPath(ExternalContext ec)
{
if(!isPortlet(ec))
{
return ec.getRequestContextPath();
}
else
{
return null;
}
}
/**
* Returns the requestURI of the HttpServletRequest or null for
* portlet requests
*
* @param ec the current external context
* @return A string containing the current request uri
*/
public static String getRequestURI(ExternalContext ec)
{
if (!isPortlet(ec))
{
return ((HttpServletRequest) ec.getRequest()).getRequestURI();
}
else
{
return null;
}
}
/**
* Returns the character encoding or null if there isn't any
*
* @param ec the current external context
* @return a string containing the request's character encoding
* @see ExternalContext#getRequestCharacterEncoding()
*
* @deprecated replaced by an API in JSF. Use ExternalContext.getRequestCharacterEncoding()
*/
@Deprecated
public static String getCharacterEncoding(ExternalContext ec)
{
return ec.getRequestCharacterEncoding();
}
/**
* Returns the name of the underlying context or null if something
* went wrong in trying to retrieve the context.
*
* @param ec the current external context
* @return a String containing the context name
*/
public static String getContextName(ExternalContext ec)
{
try
{
if (isPortlet(ec))
{
return (String) _runMethod(ec.getContext(), "getPortletContextName");
}
else
{
return ((ServletContext) ec.getContext()).getServletContextName();
}
}
catch (final ClassCastException e)
{
_LOG.severe(e.getMessage());
}
return null;
}
/**
* Returns the name and version of the underlying servlet container or null if something
* went wrong in trying to retrieve the context.
*
* @param ec the current external context
* @return a String containing the name and version of the underlying servlet container
*/
public static String getServerInfo(ExternalContext ec)
{
try
{
if (isPortlet(ec))
{
return (String) _runMethod(ec.getContext(), "getServerInfo");
}
else
{
return ((ServletContext) ec.getContext()).getServerInfo();
}
}
catch (final ClassCastException e)
{
_LOG.severe(e.getMessage());
}
return null;
}
/**
* Returns the content length or -1 if the unknown.
*
* @param ec the current external context
* @return the length or -1 if the length is unknown
*/
public static int getContentLength(ExternalContext ec)
{
if(isRequestFromClient(ec))
{
return (Integer) _runMethod(ec.getRequest(), "getContentLength");
}
return -1;
}
/**
* Returns the content type from the current externalContext or
* null if unknown.
*
* @param ec the current external context
* @return a String contining the the content type or null
* @see ExternalContext#getRequestContentType()
*
* @deprecated use ExternalContext.getRequestContentType()
*/
@Deprecated
public static String getContentType(ExternalContext ec)
{
return ec.getRequestContentType();
}
/**
* Returns the request input stream if one is available
*
* @param ec the current external context
* @return the request's input stream
* @throws IOException if there was a problem getting the input stream
*/
public static InputStream getRequestInputStream(ExternalContext ec)
throws IOException
{
RequestType type = getRequestType(ec);
if(type.isRequestFromClient())
{
Object req = ec.getRequest();
if(type.isPortlet())
{
return (InputStream)_runMethod(req, "getPortletInputStream");
}
else
{
return ((ServletRequest) ec.getRequest()).getInputStream();
}
}
return null;
}
/**
* Returns true if this externalContext represents an "action".
* An action request is any ServletRequest or a portlet ActionRequest or
* ResourceRequest.
*
* @param ec the current external context
* @return a boolean of true if this request is an action-type
* request.
* @see #isRequestFromClient(ExternalContext)
*
* @deprecated replaced with {@link #isRequestFromClient(ExternalContext)}
*/
@Deprecated
public static boolean isAction(ExternalContext ec)
{
return isRequestFromClient(ec);
}
/**
* Returns the value of {@link RequestType#isPortlet()} for the current
* RequestType. This is a convenience function designed to perform a quick
* check of the current request. If more capabilities need to be tested for
* the given request, then it is more efficient to pull this information from
* the RequestType itself.
*
* @param ec the current external context
* @return a boolean value of true if the current RequestType
* is a portlet request.
*
* @see RequestType#isPortlet()
* @see #getRequestType(ExternalContext)
*/
public static boolean isPortlet(ExternalContext ec)
{
return getRequestType(ec).isPortlet();
}
/**
* Returns the value of {@link RequestType#isResponseWritable()} for the
* current RequestType. This is a convenience function designed to perform a
* quick check of the current request. If more capabilities need to be tested
* for the given request, then it is more efficient to pull this information
* from the RequestType itself.
*
* @param ec the current external context
* @return a boolean value of true if the current RequestType
* is a "render" type response.
*
* @see RequestType#isResponseWritable()
* @see #getRequestType(ExternalContext)
* @since 2.0
*/
public static final boolean isResponseWritable(ExternalContext ec)
{
return getRequestType(ec).isResponseWritable();
}
/**
* Returns the value of {@link RequestType#isRequestFromClient()} for the
* current RequestType. This is a convenience function designed to perform a
* quick check of the current request. If more capabilities need to be tested
* for the given request, then it is more efficient to pull this information
* from the RequestType itself.
*
* @param ec the current external context
* @return a boolean value of true if the current RequestType
* represents a request from the client.
*
* @see RequestType#isResponseWritable()
* @see #getRequestType(ExternalContext)
* @since 2.0
*/
public static final boolean isRequestFromClient(ExternalContext ec)
{
return getRequestType(ec).isRequestFromClient();
}
/**
* Returns wherther of not this external context represents a true HttpServletRequest or
* not. Some portal containers implement the PortletRequest/Response objects as
* HttpServletRequestWrappers, and those objects should not be treated as an
* HttpServlerRequest. As such, this method first tests to see if the request is
* a portlet request and, if not, then tests to see if the request is an instanceof
* HttpServletRequest.
*
* @param ec the current external context
* @return a boolean value of true if the current request is an
* HttpServletRequest
* @since 1.1
*/
public static boolean isHttpServletRequest(ExternalContext ec)
{
return (!isPortlet(ec) && (ec.getRequest() instanceof HttpServletRequest));
}
/**
* Returns an HttpServletResponse if one exists on the externalContext or null
* if it does not. Please note that some portal environments implement the
* PortletRequest and Response objects as HttpServletRequest/Response objects.
* This method handles these types of requests properly and will therefore
* return null in portal environments.
*
* @param response
* @return an HttpServletResponse if we have one or null if we do not
* @since 4.0
*/
public static HttpServletResponse getHttpServletResponse(ExternalContext ec)
{
if(isHttpServletRequest(ec))
{
return (HttpServletResponse)ec.getResponse();
}
return null;
}
/**
* Runs a method on an object and returns the result
*
* @param obj the object to run the method on
* @param methodName the name of the method
* @return the results of the method run
*/
private static Object _runMethod(Object obj, String methodName)
{
try
{
Method sessionIdMethod = obj.getClass().getMethod(methodName);
return sessionIdMethod.invoke(obj);
}
catch (Exception e)
{
return null;
}
}
// prevent this from being instantiated
private ExternalContextUtils()
{}
private static final Logger _LOG = Logger.getLogger(ExternalContextUtils.class.getName());
// =-= Scott O'Bryan =-=
// Performance enhancement. These will be needed anyway, let's not get them every time.
private static final Class _PORTLET_ACTION_REQUEST_CLASS;
private static final Class _PORTLET_RENDER_REQUEST_CLASS;
private static final Class _PORTLET_RESOURCE_REQUEST_CLASS;
private static final Class _PORTLET_CONTEXT_CLASS;
private static final boolean _PORTLET_10_SUPPORTED;
private static final boolean _PORTLET_20_SUPPORTED;
static
{
Class context;
Class actionRequest;
Class renderRequest;
Class resourceRequest;
boolean portlet20Supported = false;
boolean portlet10Supported = false;
try
{
context = ClassLoaderUtils.loadClass("javax.portlet.PortletContext");
actionRequest = ClassLoaderUtils.loadClass("javax.portlet.ActionRequest");
renderRequest = ClassLoaderUtils.loadClass("javax.portlet.RenderRequest");
try
{
resourceRequest = ClassLoaderUtils.loadClass("javax.portlet.ResourceRequest");
}
catch (ClassNotFoundException e)
{
_LOG.fine("Portlet 2.0 API is not available on classpath. Portlet 2.0 functionality is disabled");
resourceRequest = null;
}
}
catch (final ClassNotFoundException e)
{
_LOG
.fine("Portlet API is not available on the classpath. Portlet configurations are disabled.");
context = null;
actionRequest = null;
renderRequest = null;
resourceRequest = null;
}
//Find bridge to tell if portal is supported
if(context != null)
{
try
{
Class bridge = ClassLoaderUtils.loadClass("javax.portlet.faces.Bridge");
if(bridge != null)
{
portlet10Supported = true;
//Standard bridge defines a spec name which can be used to
//determine Portlet 2.0 Support.
String specName = bridge.getPackage().getSpecificationTitle();
_LOG.fine("Found Bridge: " + specName);
if(specName != null && specName.startsWith("Portlet 2"))
{
portlet20Supported = true;
}
if(_LOG.isLoggable(Level.INFO))
{
String ver = (portlet20Supported)?"2.0":"1.0";
_LOG.info("Portlet Environment Detected: " + ver);
}
}
}
catch (ClassNotFoundException e)
{
_LOG.fine("Portlet API is present but bridge is not. Portlet configurations are disabled.");
}
}
_PORTLET_CONTEXT_CLASS = context;
_PORTLET_ACTION_REQUEST_CLASS = actionRequest;
_PORTLET_RENDER_REQUEST_CLASS = renderRequest;
_PORTLET_RESOURCE_REQUEST_CLASS = resourceRequest;
_PORTLET_10_SUPPORTED = portlet10Supported;
_PORTLET_20_SUPPORTED = portlet20Supported;
}
/**
* Trys to obtain a HttpServletResponse from the Response.
* Note that this method also trys to unwrap any ServletResponseWrapper
* in order to retrieve a valid HttpServletResponse.
* @param response
* @return if found, the HttpServletResponse, null otherwise
*/
public static HttpServletResponse getHttpServletResponse(Object response)
{
// unwrap the response until we find a HttpServletResponse
while (response != null)
{
if (response instanceof HttpServletResponse)
{
// found
return (HttpServletResponse) response;
}
if (response instanceof ServletResponseWrapper)
{
// unwrap
response = ((ServletResponseWrapper) response).getResponse();
}
// no more possibilities to find a HttpServletResponse
break;
}
return null; // not found
}
/**
* Trys to obtain a ResponseSwitch from the Response.
* @param response
* @return if found, the ResponseSwitch, null otherwise
*/
public static ResponseSwitch getResponseSwitch(Object response)
{
// unwrap the response until we find a ResponseSwitch
while (response != null)
{
if (response instanceof ResponseSwitch)
{
// found
return (ResponseSwitch) response;
}
if (response instanceof ServletResponseWrapper)
{
// unwrap
response = ((ServletResponseWrapper) response).getResponse();
}
// no more possibilities to find a ResponseSwitch
break;
}
return null; // not found
}
/**
* Try to create a ResponseSwitch for this response.
* @param response
* @return the created ResponseSwitch, if there is a ResponseSwitch
* implementation for the given response, null otherwise
*/
public static ResponseSwitch createResponseSwitch(Object response)
{
if (response instanceof HttpServletResponse)
{
return new HttpServletResponseSwitch((HttpServletResponse) response);
}
else if (response instanceof ServletResponse)
{
return new ServletResponseSwitch((ServletResponse) response);
}
return null;
}
}