[[UrlRewrite-UrlRewriteComponent]]
UrlRewrite Component
~~~~~~~~~~~~~~~~~~~~

*Available as of Camel 2.11*

The `camel-urlrewrite` component allows to plugin url rewrite
functionality to <<http-component,HTTP>>, <<http-component,HTTP4>>,
<<jetty-component,Jetty>>, or <<jetty-component,AHC>> components. This component
integrates the
http://code.google.com/p/urlrewritefilter/[UrlRewriteFilter] project
with Apache Camel. This allows you to use the capabilities from the url
rewrite project with your Camel routes.

This component *requires* that your Camel routes starts from a servlet
based endpoint such as <<jetty-component,Jetty>> or
<<servlet-component,SERVLET>>.

[[UrlRewrite-Options]]
Options
^^^^^^^

The `camel-urlrewrite` component offers the following options

[width="100%",cols="10%,10%,80%",options="header",]
|=======================================================================
|Name |Default Value |Description

|`conf` |`null` |To use a custom `org.tuckey.web.filters.urlrewrite.Conf` as the
configuration for the url rewrite filter.

|`configFile` |`null` |Refers to a file name to load as the configuration file. The file should
be XML file.

|`modRewriteConfFile` |`null` |Refers to a file name to load as the Apache mod_rewrite style based
configuration file. This file should be a plain text file.

|`modRewriteConfText` |`null` |Is used to quickly configure a Apache mod_rewrite style based
configuration without using a file.

|`useQueryString` |`false` |Whether to use query strings in the url rewrite rules.

|`useContext` |`false` |Whether to include context-path or not in the matching. Will be default
remove the context-path.

|`defaultMatchType` |`"regex"` |Which match type to use. Can be either "wildcard" or "regex".

|`decodeUsing` |`null` |To use a specific encoding such as "utf-8" or "iso-8859-1".
|=======================================================================

[[UrlRewrite-Usage]]
Usage
^^^^^

The following component producers supports using together with the
`camel-urlrewrite` component: <<http-component,HTTP>>,
<<http4-component,HTTP4>> and <<http4-component,Jetty>>.

[width="100%",cols="10%,90%",options="header",]
|=======================================================================
|Component |Class
|`camel-http` | *Camel 2.15 or
older:*` org.apache.camel.component.urlrewrite.http.HttpUrlRewrite`

|`camel-jetty` |*Camel 2.15 or
older:*org.apache.camel.component.urlrewrite.http.HttpUrlRewrite

|`camel-http4` |*Camel 2.15 or
older:*org.apache.camel.component.urlrewrite.http4.HttpUrlRewrite
|=======================================================================

From *Camel 2.16* onwards this is no longer necessary and there is only
one class, which
is `org.apache.camel.component.urlrewrite.HttpUrlRewrite` that works
with any of the components.

You setup the url rewrite as a bean of the type
`org.apache.camel.component.urlrewrite.http.HttpUrlRewrite` (when using
<<http-component,HTTP>> component) as shown below:

And in XML DSL you can do:

[source,xml]
----------------------------------------------------------------------------------
<bean id="myRewrite" class="org.apache.camel.component.urlrewrite.HttpUrlRewrite">
  <property name="configFile" value="example/urlrewrite2.xml"/>
</bean>
----------------------------------------------------------------------------------

In the bean above we configure it with the `configFile` option which is
a XML http://code.google.com/p/urlrewritefilter/[UrlRewriteFilter]
configuration file.


TIP:See more details at
http://code.google.com/p/urlrewritefilter/[UrlRewriteFilter] for how to
configure the XML rules file.

In the Camel routes, you bridge the endpoints, and refer to the url
rewrite on the producer endpoint as shown below. Notice how we refer to
our url rewrite filter using the `urlRewrite` option in the endpoint
uri.

[[UrlRewrite-Usingloadbalancingeip]]
Using load balancing eip
++++++++++++++++++++++++

You can also use Camel's Load Balancer together
with UrlRewrite, as shown below. In this code we
use the failover load balancer, to failover to the 2nd endpoint (which
goes to myapp3) in case of any exception thrown.

[[UrlRewrite-UsingApachemod_rewritestyleconfiguration]]
Using Apache mod_rewrite style configuration
++++++++++++++++++++++++++++++++++++++++++++

The http://code.google.com/p/urlrewritefilter/[UrlRewriteFilter] project
also supports Apache mod_rewrite style configuration.

For example to configure the bean using the modRewriteConfFile property
to refer to a mod configuration file:

[source,xml]
----------------------------------------------------------------------------------
<bean id="myRewrite" class="org.apache.camel.component.urlrewrite.HttpUrlRewrite">
  <property name="modRewriteConfFile" value="example/modrewrite.cxf"/>
</bean>
----------------------------------------------------------------------------------

Which then can contain mod rewrite rules and the likes:

You can have multiple RewriteRule rules and other configurations. See
more details at
http://code.google.com/p/urlrewritefilter/[UrlRewriteFilter] project.

[[UrlRewrite-Writingcustomurlrewriters]]
Writing custom url rewriters
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

You can implement your custom url rewriters by implementing either of
the following interfaces from the component of choice:

Component(s): camel-http / camel-jetty

* `org.apache.camel.component.http.UrlRewrite`
* `org.apache.camel.component.http.HttpServletUrlRewrite`

Component(s): camel-http4

* `org.apache.camel.component.http4.UrlRewrite`
* `org.apache.camel.component.http4.HttpServletUrlRewrite`

The former is a simple and generic interface, which is not dependent on
the Servlet API. The later is servlet based which requires the Camel route to start from
a servlet based component such as <<jetty-component,Jetty>> or
<<servlet-component,SERVLET>>. The servlet based is more feature rich and
that's the API we use to integrate with the
http://code.google.com/p/urlrewritefilter/[UrlRewriteFilter] project in
this `camel-urlrewrite` component.

[[UrlRewrite-Asimpleurlrewritefilter]]
A simple url rewrite filter
+++++++++++++++++++++++++++

In this example we implement a custom
`org.apache.camel.component.http.UrlRewrite` that just replaces yahoo
with google. Mind this example is based on a unit test, and only for
demonstration purposes. As its java code you have full power to
implement more complex logic.

The url parameter contains the full url including
scheme://hostname:port/path?query. The relativeUrl parameter is the url
without the endpoint configured path. Notice this option may be null if
the url doesn't start with the endpoint configured path.

[[UrlRewrite-SeeAlso]]
See Also
^^^^^^^^

* Configuring Camel
* Component
* Endpoint
* Getting Started

* <<jetty-component,Jetty>>
* <<http4-component,HTTP4>>
* <<http-component,HTTP>>
* <<ahc-component,AHC>>

