org.apache.myfaces.webapp.filter.ExtensionsFilter Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing,
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package org.apache.myfaces.webapp.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileUpload;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.myfaces.renderkit.html.util.AddResource;
import org.apache.myfaces.renderkit.html.util.AddResourceFactory;
/**
* This filter provides a number of functions that many tomahawk components require.
*
* In tomahawk versions up to and including 1.1.6, it is mandatory to define this filter in the application's
* web.xml in order to use some tomahawk components. In Tomahawk version 1.1.7, this filter is now optional;
* when defined it will be used as for earlier versions. When omitted, the same functionality is now
* automatically provided via classes TomahawkFacesContextFactory and ServeResourcePhaseListener.
*
*
Response Buffering
*
* When the request is for a JSF page, and the configured "resource manager"
* requires response buffering then a response wrapper is created which
* buffers the entire output from the current request in memory.
*
* Tomahawk provides at least three "resource managers":
*
* - DefaultAddResources (the default) does require response buffering.
*
- NonBufferingAddResource does not require response buffering, but it
* renders javascript on body and offer support in portlets enviroments.
*
- StreamingAddResources does not, but only provides a subset of the
* features of DefaultAddResources and therefore does not work with all
* Tomahawk components.
*
*
* Only one "resource manager" may be configured for a webapp. See class
* AddResourceFactory for further details on configuring this.
*
* When DefaultAddResources is enabled (default behaviour), the resulting
* response buffering does cause some unnecessary memory and performance
* impact for pages where no component in the page actually registers a
* resource that needs to be inserted into the page - but whether a page
* does that or not cannot be known until after the page has been rendered.
* In the rare case where a request to a JSF page generates non-html
* output (eg a PDF is generated as a response to a submit of a jsf page),
* the data is unfortunately buffered. However it is not post-processed,
* because its http content-type header will not be "text/html" (see other
* documentation for this class).
*
*
Inserting Resources into HTML responses (DefaultAddResources)
*
* After the response has been completely generated (and cached in memory),
* this filter checks the http content-type header. If it is not html or xhtml,
* then the data is simply send to the response stream without further processing.
*
* For html or xhtml responses, this filter causes the data to be post-processed
* to insert any "resources" registered via the AddResources framework. This
* allows jsf components (and other code if it wants) to register data that
* should be output into an HTML page, particularly into places like an html
* "head" section, even when the component occurs after that part of the
* response has been generated.
*
* The default "resource manager" (DefaultAddResources) supports inserting
* resources into any part of the generated page. The alternate class
* StreamingAddResources does not; it does not buffer output and therefore
* can only insert resources for a jsf component into the page after the
* point at which that component is rendered. In particular, this means that
* components that use external javascript files will not work with that
* "resource manager" as [script href=...] only works in the head section
* of an html page.
*
*
Serving Resources from the Classpath
*
* Exactly what text gets inserted into an HTML page via a "resource"
* (see above) is managed by the AddResources class, not this one. However
* often it is useful for jsf components to be able to refer to resources
* that are on the classpath, and in particular when the resource is in the
* same jar as the component code. Servlet engines do not support serving
* resources from the classpath. However the AddResources framework can be
* used to generate a special url prefix that this filter can be mapped to,
* allowing this to be done. In particular, many Tomahawk components use
* this to bundle their necessary resources within the tomahawk jarfile.
*
* When a request to such a url is found by this filter, the actual resource
* is located and streamed back to the user (no buffering required). See the
* AddResource class documentation for further details.
*
*
Handling File Uploads
*
* Sometimes an application needs to allow a user to send a file of data
* to the web application. The html page needs only to include an input
* tag with type=file; clicking on this will prompt the user for a file
* to send. The browser will then send an http request to the server
* which is marked as a "mime multipart request" with normal http post
* parameters in one mime part, and the file contents in another mime part.
*
* This filter also handles such requests, using the Apache HttpClient
* library to save the file into a configurable local directory before
* allowing the normal processing for the url that the post request
* refers to. A number of configuration properties on this filter control
* maximum file upload sizes and various other useful settings. See the
* documentation for the init method for more details.
*
*
Avoiding Processing
*
* When the ExtensionsFilter is enabled, and the DefaultAddResources
* implementation is used then there is no way to avoid having the
* response buffered in memory. However as long as the mime-type set
* for the response data is not text/html then the data will
* be written out without any modifications.
*
* @author Sylvain Vieujot (latest modification by $Author: skitching $)
* @version $Revision: 692393 $ $Date: 2008-09-05 04:26:40 -0500 (Fri, 05 Sep 2008) $
*/
public class ExtensionsFilter implements Filter {
private Log log = LogFactory.getLog(ExtensionsFilter.class);
private int _uploadMaxFileSize = 100 * 1024 * 1024; // 100 MB
private int _uploadThresholdSize = 1 * 1024 * 1024; // 1 MB
private String _uploadRepositoryPath = null; //standard temp directory
private ServletContext _servletContext;
public static final String DOFILTER_CALLED = "org.apache.myfaces.component.html.util.ExtensionFilter.doFilterCalled";
/**
* Init method for this filter.
*
* The following filter init parameters can be configured in the web.xml file
* for this filter:
*
* - uploadMaxFileSize
* - uploadThresholdSize
* - uploadRepositoryPath
*
*
*
* All size parameters may have the suffix "g" (gigabytes), "m" (megabytes) or "k" (kilobytes).
*
*
* uploadMaxFileSize
*
* Sets the maximum allowable size for uploaded files.
*
* If the user attempts to upload a file which is larger than this, then the data is
* transmitted from the browser to the server (this cannot be prevented with standard HTML
* functionality). However the file will not be saved in memory or on disk. An error message
* will be added to the standard JSF error messages, and the page re-rendered (as for a
* validation failure).
*
*
* The default value is 100 Megabytes.
*
*
* uploadThresholdSize
*
* Sets the size threshold beyond which files are written directly to disk. Files which are
* smaller than this are simply held in memory. The default is 1 Megabyte.
*
* uploadRepositoryPath
*
* Sets the directory in which temporary files (ie caches for those uploaded files that
* are larger than uploadThresholdSize) are to be stored.
*/
public void init(FilterConfig filterConfig) {
// Note that the code here to extract FileUpload configuration params is not actually used.
// The handling of multipart requests was moved from this Filter into a custom FacesContext
// (TomahawkFacesContextWrapper) so that Portlets could be supported (Portlets cannot use
// servlet filters).
//
// For backwards compatibility, the TomahawkFacesContextWrapper class *parses* the
// web.xml to retrieve these same filter config params. That is IMO seriously ugly
// and hopefully will be fixed.
String param = filterConfig.getInitParameter("uploadMaxFileSize");
_uploadMaxFileSize = resolveSize(param, _uploadMaxFileSize);
param = filterConfig.getInitParameter("uploadThresholdSize");
_uploadThresholdSize = resolveSize(param, _uploadThresholdSize);
_uploadRepositoryPath = filterConfig.getInitParameter("uploadRepositoryPath");
_servletContext = filterConfig.getServletContext();
}
private int resolveSize(String param, int defaultValue) {
int numberParam = defaultValue;
if (param != null) {
param = param.toLowerCase();
int factor = 1;
String number = param;
if (param.endsWith("g")) {
factor = 1024 * 1024 * 1024;
number = param.substring(0, param.length() - 1);
} else if (param.endsWith("m")) {
factor = 1024 * 1024;
number = param.substring(0, param.length() - 1);
} else if (param.endsWith("k")) {
factor = 1024;
number = param.substring(0, param.length() - 1);
}
numberParam = Integer.parseInt(number) * factor;
}
return numberParam;
}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
if(request.getAttribute(DOFILTER_CALLED)!=null)
{
chain.doFilter(request, response);
return;
}
request.setAttribute(DOFILTER_CALLED,"true");
if (!(response instanceof HttpServletResponse)) {
//If this is a portlet request, just continue the chaining
chain.doFilter(request, response);
return;
}
HttpServletResponse httpResponse = (HttpServletResponse) response;
HttpServletRequest httpRequest = (HttpServletRequest) request;
// Serve resources
AddResource addResource;
try
{
addResource = AddResourceFactory.getInstance(httpRequest,_servletContext);
if( addResource.isResourceUri(_servletContext, httpRequest ) ){
addResource.serveResource(_servletContext, httpRequest, httpResponse);
return;
}
}
catch(Throwable th)
{
log.error("Exception wile retrieving addResource",th);
throw new ServletException(th);
}
HttpServletRequest extendedRequest = httpRequest;
// For multipart/form-data requests
// This is done by TomahawkFacesContextWrapper
if (FileUpload.isMultipartContent(httpRequest)) {
extendedRequest = new MultipartRequestWrapper(httpRequest, _uploadMaxFileSize, _uploadThresholdSize, _uploadRepositoryPath);
}
try
{
addResource.responseStarted();
//This case is necessary when is used
//org.apache.myfaces.renderkit.html.util.DefaultAddResource
//Buffers the output and add to the header the necessary stuff
//In other case this is simply ignored (NonBufferingAddResource and
//StreamingAddResource), because this not require buffering
//and the chaining continues.
if (addResource.requiresBuffer())
{
ExtensionsResponseWrapper extendedResponse = new ExtensionsResponseWrapper((HttpServletResponse) response);
// Standard request
chain.doFilter(extendedRequest, extendedResponse);
extendedResponse.finishResponse();
// write the javascript stuff for myfaces and headerInfo, if needed
HttpServletResponse servletResponse = (HttpServletResponse)response;
// only parse HTML responses
if (extendedResponse.getContentType() != null && isValidContentType(extendedResponse.getContentType()))
{
addResource.parseResponse(extendedRequest, extendedResponse.toString(),
servletResponse);
addResource.writeMyFacesJavascriptBeforeBodyEnd(extendedRequest,
servletResponse);
if( ! addResource.hasHeaderBeginInfos() ){
// writes the response if no header info is needed
addResource.writeResponse(extendedRequest, servletResponse);
return;
}
// Some headerInfo has to be added
addResource.writeWithFullHeader(extendedRequest, servletResponse);
// writes the response
addResource.writeResponse(extendedRequest, servletResponse);
}
else
{
byte[] responseArray = extendedResponse.getBytes();
if(responseArray.length > 0)
{
// When not filtering due to not valid content-type, deliver the byte-array instead of a charset-converted string.
// Otherwise a binary stream gets corrupted.
servletResponse.getOutputStream().write(responseArray);
}
}
}
else
{
chain.doFilter(extendedRequest, response);
}
}
finally
{
addResource.responseFinished();
}
//chain.doFilter(extendedRequest, response);
}
public boolean isValidContentType(String contentType)
{
return contentType.startsWith("text/html") ||
contentType.startsWith("text/xml") ||
contentType.startsWith("application/xhtml+xml") ||
contentType.startsWith("application/xml");
}
/**
* Destroy method for this filter
*/
public void destroy() {
// NoOp
}
}