JavaScript

Overview

JavaScript, also known as ECMAScript is a Java-based scripting language that allows quick parsing of object. The JavaScript support is part of the camel-script module.

Adding the script module

To use JavaScript in your routes you need to add a dependency on camel-script to your project as shown in Example 5.

Example 5. Adding the camel-script dependency

<!-- Maven POM File -->
<properties>
  <camel-version>2.10.0-fuse-00-05</camel-version>
  ...
</properties>

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

Static import

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

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

Built-in attributes

Table 5 lists the built-in attributes that are accessible when using JavaScript.

Table 5. JavaScript attributes

Attribute	Type	Value
`context`	`org.apache.camel.CamelContext`	The Camel Context
`exchange`	`org.apache.camel.Exchange`	The current Exchange
`request`	`org.apache.camel.Message`	The IN message
`response`	`org.apache.camel.Message`	The OUT message
`properties`	`org.apache.camel.builder.script.PropertiesFunction`	Function with a `resolve` method to make it easier to use the properties component inside scripts.

The attributes all set at ENGINE_SCOPE.

Example

Example 6 shows a route that uses JavaScript.

Example 6. Route using JavaScript

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

Using the properties component

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

.setHeader("myHeader").javaScript("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 EIP Component Reference.

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