org.tuckey.web.filters.urlrewrite
Class UrlRewriteFilter

java.lang.Object
  org.tuckey.web.filters.urlrewrite.UrlRewriteFilter

All Implemented Interfaces:

javax.servlet.Filter

Direct Known Subclasses:

SampleMultiUrlRewriteFilter

public class UrlRewriteFilter
extends Object
implements javax.servlet.Filter

Based on the popular and very useful mod_rewrite for apache, UrlRewriteFilter is a Java Web Filter for any J2EE compliant web application server (such as Resin or Tomcat), which allows you to rewrite URLs before they get to your code. It is a very powerful tool just like Apache's mod_rewrite.

The main things it is used for are:

• URL Tidyness - keep URLs tidy irrespective of the underlying technology (JSPs, servlets, struts etc).
• Browser Detection - Allows you to rewrite URLs based on request HTTP headers (such as "user-agent").
• Date based rewriting - Allows you to forward or redirect to other URL's based on the date/time.

UrlRewriteFilter uses an xml file, called urlrewrite.xml (lives in the WEB-INF directory), for configuration. Most parameters can be Perl5 style Regular Expressions or Wildcards (i.e. *). This makes it very powerful indeed.

Special thanks to all those who gave patches/feedback especially Vineet Kumar.

Thanks also to Ralf S. Engelschall (www.engelschall.com) the inventor of mod_rewrite.

Version:

$Revision: 51 $ $Date: 2006-12-08 11:37:07 +1300 (Fri, 08 Dec 2006) $

Author:

Paul Tuckey

Field Summary

static String	DEFAULT_MOD_REWRITE_STYLE_CONF_PATH
static String	DEFAULT_WEB_CONF_PATH
static String	VERSION Deprecated. use getFullVersionString.

Constructor Summary

UrlRewriteFilter()

Method Summary

protected void	checkConf(Conf conf) Separate from checkConfLocal so that it can be overidden.
void	destroy() Destroy is called by the application server when it unloads this filter.
void	destroyActual()
protected void	destroyUrlRewriter()
void	doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain) The main method called for each request that this filter is mapped for.
int	getConfReloadCheckInterval() The amount of seconds between reload checks.
Date	getConfReloadLastCheck()
static String	getFullVersionString()
String	getStatusPath()
protected UrlRewriter	getUrlRewriter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain) Called for every request.
void	init(javax.servlet.FilterConfig filterConfig) Init is called automatically by the application server when it creates this filter.
boolean	isConfReloadCheckEnabled()
boolean	isLoaded()
boolean	isStatusEnabled()
boolean	isTimeToReloadConf() Is it time to reload the configuration now.
protected void	loadUrlRewriter(javax.servlet.FilterConfig filterConfig) Separate from init so that it can be overidden.
void	reloadConf() Forcibly reload the configuration now.

Methods inherited from class java.lang.Object

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

Field Detail

VERSION

public static final String VERSION

Deprecated. use getFullVersionString.

See Also:

Constant Field Values

DEFAULT_WEB_CONF_PATH

public static final String DEFAULT_WEB_CONF_PATH

See Also:

Constant Field Values

DEFAULT_MOD_REWRITE_STYLE_CONF_PATH

public static final String DEFAULT_MOD_REWRITE_STYLE_CONF_PATH

See Also:

Constant Field Values

Constructor Detail

UrlRewriteFilter

public UrlRewriteFilter()

Method Detail

init

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

Init is called automatically by the application server when it creates this filter.

Specified by:

init in interface javax.servlet.Filter

Parameters:

filterConfig - The config of the filter

Throws:

javax.servlet.ServletException

loadUrlRewriter

protected void loadUrlRewriter(javax.servlet.FilterConfig filterConfig)
                        throws javax.servlet.ServletException

Separate from init so that it can be overidden.

Throws:

javax.servlet.ServletException

checkConf

protected void checkConf(Conf conf)

Separate from checkConfLocal so that it can be overidden.

destroy

public void destroy()

Destroy is called by the application server when it unloads this filter.

Specified by:

destroy in interface javax.servlet.Filter

destroyActual

public void destroyActual()

destroyUrlRewriter

protected void destroyUrlRewriter()

doFilter

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

The main method called for each request that this filter is mapped for.

Specified by:

doFilter in interface javax.servlet.Filter

Parameters:

request - the request to filter

response - the response to filter

chain - the chain for the filtering

Throws:

IOException

javax.servlet.ServletException

getUrlRewriter

protected UrlRewriter getUrlRewriter(javax.servlet.ServletRequest request,
                                     javax.servlet.ServletResponse response,
                                     javax.servlet.FilterChain chain)

Called for every request.

Split from doFilter so that it can be overriden.

isTimeToReloadConf

public boolean isTimeToReloadConf()

Is it time to reload the configuration now. Depends on is conf reloading is enabled.

reloadConf

public void reloadConf()

Forcibly reload the configuration now.

isConfReloadCheckEnabled

public boolean isConfReloadCheckEnabled()

getConfReloadCheckInterval

public int getConfReloadCheckInterval()

The amount of seconds between reload checks.

Returns:

int number of millis

getConfReloadLastCheck

public Date getConfReloadLastCheck()

isStatusEnabled

public boolean isStatusEnabled()

getStatusPath

public String getStatusPath()

isLoaded

public boolean isLoaded()

getFullVersionString

public static String getFullVersionString()