org.apache.wicket.protocol.http
Class WicketFilter

java.lang.Object
  org.apache.wicket.protocol.http.WicketFilter

All Implemented Interfaces:

javax.servlet.Filter

Direct Known Subclasses:

ReloadingWicketFilter

public class WicketFilter
extends java.lang.Object
implements javax.servlet.Filter

Filter for initiating handling of Wicket requests.

For 1.3 and onward, what we do is instead of using a servlet, use a filter.

The advantage of a filter is that, unlike a servlet, it can choose not to process the request and let whatever is next in chain try. So when using a Wicket filter and a request comes in for foo.gif the filter can choose not to process it because it knows it is not a wicket-related request. Since the filter didn't process it, it falls on to the application server to try, and then it works."

Author:

Jonathan Locke, Timur Mehrvarz, Juergen Donnerstag, Igor Vaynberg (ivaynberg), Al Maw, jcompagner

See Also:

for documentation

Field Summary

static java.lang.String	APP_FACT_PARAM The name of the context parameter that specifies application factory class
static java.lang.String	FILTER_MAPPING_PARAM The name of the root path parameter that specifies the root dir of the app.
static java.lang.String	IGNORE_PATHS_PARAM Name of parameter used to express a comma separated list of paths that should be ignored

Constructor Summary

WicketFilter()

Method Summary

protected void	createRequestContext(WebRequest request, WebResponse response)
void	destroy() Servlet cleanup.
void	doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain) As per Filter.doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain), is called by the container each time a request/response pair is passed through the chain due to a client request for a resource at the end of the chain.
boolean	doGet(javax.servlet.http.HttpServletRequest servletRequest, javax.servlet.http.HttpServletResponse servletResponse) Handles servlet page requests, delegating to the wicket RequestCycle system.
protected IWebApplicationFactory	getApplicationFactory() Creates the web application factory instance.
protected java.lang.ClassLoader	getClassLoader()
javax.servlet.FilterConfig	getFilterConfig()
protected java.lang.String	getFilterPath(javax.servlet.http.HttpServletRequest request)
java.lang.String	getRelativePath(javax.servlet.http.HttpServletRequest request) Returns a relative path to the filter path and context root from an HttpServletRequest - use this to resolve a Wicket request.
void	init(javax.servlet.FilterConfig filterConfig) As per Filter.init(FilterConfig), is called by the web container to indicate to a filter that it is being placed into service.
protected boolean	isPortletContextAvailable(javax.servlet.FilterConfig config) Tries to find if a PortletContext is available.
protected WicketFilterPortletContext	newWicketFilterPortletContext()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

APP_FACT_PARAM

public static final java.lang.String APP_FACT_PARAM

The name of the context parameter that specifies application factory class

See Also:

Constant Field Values

FILTER_MAPPING_PARAM

public static final java.lang.String FILTER_MAPPING_PARAM

The name of the root path parameter that specifies the root dir of the app.

See Also:

Constant Field Values

IGNORE_PATHS_PARAM

public static final java.lang.String IGNORE_PATHS_PARAM

Name of parameter used to express a comma separated list of paths that should be ignored

See Also:

Constant Field Values

Constructor Detail

WicketFilter

public WicketFilter()

Method Detail

destroy

public void destroy()

Servlet cleanup.

Specified by:

destroy in interface javax.servlet.Filter

doFilter

public void doFilter(javax.servlet.ServletRequest request,
                     javax.servlet.ServletResponse response,
                     javax.servlet.FilterChain chain)
              throws java.io.IOException,
                     javax.servlet.ServletException

As per Filter.doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain), is called by the container each time a request/response pair is passed through the chain due to a client request for a resource at the end of the chain. The FilterChain passed in to this method allows the Filter to pass on the request and response to the next entity in the chain.

Delegates to doGet(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) for actual response rendering.

doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain) goes through a series of steps of steps to process a request;

1. If running in a portlet context, sets up the WicketFilterPortletContext retrieving the portlet specific (PortletServletRequestWrapper and PortletServletResponseWrapper) wrapped request and response objects.
2. Otherwise retrieves standard HttpServletRequest and HttpServletResponse objects.
3. Passes on requests down the filter chain if configured as a portlet _only_ filter but not running in a portlet context. USE CASE IS WHAT?
4. Checks against registered ignore paths, and passes the request on down the chain if a match is found.
5. Pass the request to underling servlet style doGet(HttpServletRequest, HttpServletResponse) to attempt actually rendering the response Wicket style.
6. Potentially respond with "not-modified" for resource type requests
7. Finally pass on the request if we didn't handle it

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

java.io.IOException

javax.servlet.ServletException

See Also:

WicketFilterPortletContext, PortletServletRequestWrapper, PortletServletResponseWrapper, Filter.doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)

doGet

public boolean doGet(javax.servlet.http.HttpServletRequest servletRequest,
                     javax.servlet.http.HttpServletResponse servletResponse)
              throws javax.servlet.ServletException,
                     java.io.IOException

Handles servlet page requests, delegating to the wicket RequestCycle system.

1. Checks for the an effective home page request and redirects appropriately.
2. Check for REDIRECT_TO_BUFFER case and redirect to a buffered response if one exists.
3. Otherwise begins the RequestCycle processing.

Parameters:

servletRequest - Servlet request object

servletResponse - Servlet response object

Returns:

true if the request was handled by wicket, false otherwise

Throws:

javax.servlet.ServletException - Thrown if something goes wrong during request handling

java.io.IOException

See Also:

RequestCycle

getFilterConfig

public javax.servlet.FilterConfig getFilterConfig()

Returns:

The filter config of this WicketFilter

getRelativePath

public java.lang.String getRelativePath(javax.servlet.http.HttpServletRequest request)

Returns a relative path to the filter path and context root from an HttpServletRequest - use this to resolve a Wicket request.

Parameters:

request -

Returns:

Path requested, minus query string, context path, and filterPath. Relative, no leading '/'.

init

public void init(javax.servlet.FilterConfig filterConfig)
          throws javax.servlet.ServletException

As per Filter.init(FilterConfig), is called by the web container to indicate to a filter that it is being placed into service. init(FilterConfig) goes through a series of steps of steps to initialise;

1. Sets up ignore paths
2. Records class loaders
3. Finds the filter's path - filterPath
4. Sets up the IWebApplicationFactory and WebApplication for this filter, including it's initialisation.
5. Initialise WebApplication request listeners.
6. Log start of Application
7. Detect if running in a Portlet context and if so intialise the WicketFilterPortletContext

Specified by:

init in interface javax.servlet.Filter

Throws:

javax.servlet.ServletException

See Also:

Filter.init(javax.servlet.FilterConfig)

isPortletContextAvailable

protected boolean isPortletContextAvailable(javax.servlet.FilterConfig config)
                                     throws javax.servlet.ServletException

Tries to find if a PortletContext is available. Searches for the 'detect portlet context' flag in various places and if true, tries to load the PortletContext.

Parameters:

config - the FilterConfig object

Returns:

true if PortletContext was successfully loaded

Throws:

javax.servlet.ServletException - on IO errors

newWicketFilterPortletContext

protected WicketFilterPortletContext newWicketFilterPortletContext()

createRequestContext

protected void createRequestContext(WebRequest request,
                                    WebResponse response)

getApplicationFactory

protected IWebApplicationFactory getApplicationFactory()

Creates the web application factory instance. If no APP_FACT_PARAM is specified in web.xml ContextParamWebApplicationFactory will be used by default.

Returns:

application factory instance

See Also:

ContextParamWebApplicationFactory

getClassLoader

protected java.lang.ClassLoader getClassLoader()

Returns:

The class loader

getFilterPath

protected java.lang.String getFilterPath(javax.servlet.http.HttpServletRequest request)