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, Orion 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.

URL rewriting is very common with Apache Web Server (see mod_rewrite's rewriting guide) but has not been possible in most java web application servers. The main things it is used for are:

• URL Tidyness / URL Abstraction - keep URLs tidy irrespective of the underlying technology or framework (JSP, Servlet, Struts etc).
• Browser Detection - Allows you to rewrite URLs based on request HTTP headers (such as user-agent or charset).
• Date based rewriting - Allows you to forward or redirect to other URL's based on the date/time (good for planned outages).
• Moved content - enable a graceful move of content or even a change in CMS.
• Tiny/Friendly URL's (i.e. blah.com/latest can be redirected to blah.com/download/ver1.2.46.2/setup.exe)
• A Servlet mapping engine (see Method Invocation)

!UrlRewriteFilter uses an xml file, called urlrewrite.xml (it goes into the WEB-INF directory), for configuration. Most parameters can be Perl5 style Regular Expressions or Wildcard Expressions. This makes it very powerful indeed.

See the manual for more information.

• Add Maven dependency below or add urlrewritefilter-4.0.3.jar directly into your WEB-INF/lib directory.

    <dependency>
        <groupId>org.tuckey</groupId>
        <artifactId>urlrewritefilter</artifactId>
        <version>4.0.3</version>
    </dependency>

• Add the following to your WEB-INF/web.xml (add it near the top above your servlet mappings (if you have any)): (see filter parameters for more options)

    <filter>
        <filter-name>UrlRewriteFilter</filter-name>
        <filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>UrlRewriteFilter</filter-name>
        <url-pattern>/*</url-pattern>
        <dispatcher>REQUEST</dispatcher>
        <dispatcher>FORWARD</dispatcher>
    </filter-mapping>

• Add urlrewrite.xml into your WEB-INF directory. (src/main/webapp/WEB-INF/ for Maven users)
• Restart the context.

You can visit http://127.0.0.1:8080/rewrite-status (or whatever the address of your local webapp and context) to see output (note: this page is only viewable from localhost).

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Previously on Google Code: http://code.google.com/p/urlrewritefilter.