Available as of Camel 2.11
camel-urlrewrite component allows to plugin url rewrite functionality to HTTP, HTTP4, Jetty, or AHC components. This component integrates the UrlRewriteFilter project with Apache Camel. This allows you to use the capabilities from the url rewrite project with your Camel routes.
camel-urlrewrite component offers the following options
To use a custom
Refers to a file name to load as the configuration file. The file should be XML file.
Refers to a file name to load as the Apache mod_rewrite style based configuration file. This file should be a plain text file.
Is used to quickly configure a Apache mod_rewrite style based configuration without using a file.
Whether to use query strings in the url rewrite rules.
Whether to include context-path or not in the matching. Will be default remove the context-path.
Which match type to use. Can be either "wildcard" or "regex".
To use a specific encoding such as "utf-8" or "iso-8859-1".
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) as shown below:
In the bean above we configure it with the
configFile option which is a XML UrlRewriteFilter configuration file.
See more details at 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.
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.
Using Apache mod_rewrite style configuration
The 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:
Which then can contain mod rewrite rules and the likes:You can have multiple RewriteRule rules and other configurations. See more details at UrlRewriteFilter project.
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
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 or SERVLET. The servlet based is more feature rich and that's the API we use to integrate with the UrlRewriteFilter project in this
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.