Chapter 27. Python

Python is a remarkably powerful dynamic programming language that is used in a wide variety of application domains. Python is often compared to Tcl, Perl, Ruby, Scheme or Java. The Python support is part of the camel-script module.

To use Python in your routes you need to add a dependency on camel-script to your project as shown in Example 27.1, “Adding the camel-script dependency”.

<!-- Maven POM File -->
...
<dependencies>
  ...
  <dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-script</artifactId>
    <version>${camel-version}</version>
  </dependency>
  ...
</dependencies>

To use the python() static method in your application code, include the following import statement in your Java source files:

import static org.apache.camel.builder.script.ScriptBuilder.*;

Table 27.1, “Python attributes” lists the built-in attributes that are accessible when using Python.

The attributes all set at ENGINE_SCOPE.

Example 27.2, “Route using Python” shows a route that uses Python.

<camelContext>
  <route>
    <from uri="direct:start"/>
    <choice>
      <when>
        <langauge langauge="python">if request.headers.get('user') = 'admin'</langauge>
        <to uri="seda:adminQueue"/>
      </when>
      <otherwise>
        <to uri="seda:regularQueue"/>
      </otherwise>
    </choice>
  </route>
</camelContext>

To access a property value from the properties component, invoke the resolve method on the built-in properties attribute, as follows:

.setHeader("myHeader").python("properties.resolve(PropKey)")

Where PropKey is the key of the property you want to resolve, where the key value is of String type.

For more details about the properties component, see Properties in the Apache Camel Component Reference Guide.