Camel Components

Set Header

The SetHeader EIP is used for setting a message header.

Options

The Set Header eip supports the following options which are listed below.

Name Description Default Type

note

The note for this node.

String

description

The description for this node.

String

disabled

Whether to disable this EIP from the route during build time. Once an EIP has been disabled then it cannot be enabled later at runtime.

false

Boolean

name

Required Name of message header to set a new value. The simple language can be used to define a dynamic evaluated header name. Otherwise a constant name will be used.

String

expression

Required The expression whose result is used as the header value.

ExpressionDefinition

Message Body

The message body at each side of the Set Header EIP: EIP input is the body it needs, EIP output the body after it, and Steps the body its own steps start with.

Side Body Description

EIP output

unchanged

Sets a header: the body stays as it was.

The bodies are the ones with the default options. A side that is not listed is not known, and tooling does not guess it. The carriers are described in the Camel Catalog.

Exchange properties

The Set Header eip has no exchange properties.

Using Set Header

The following example shows how to set a header in a Camel route:

  • Java

  • XML

  • YAML

from("direct:a")
    .setHeader("myHeader", constant("test"))
    .to("direct:b");
<route>
    <from uri="direct:a"/>
    <setHeader name="myHeader">
        <constant>test</constant>
    </setHeader>
    <to uri="direct:b"/>
</route>
- route:
    from:
      uri: direct:a
      steps:
        - setHeader:
            name: myHeader
            expression:
              constant:
                expression: test
        - to:
            uri: direct:b

In the example, the header value is a constant.

Any of the Camel languages can be used, such as Simple.

  • Java

  • XML

  • YAML

from("direct:a")
    .setHeader("randomNumber", simple("${random(1,100)}"))
    .to("direct:b");

Header can be set using fluent syntax.

from("direct:a")
    .setHeader("randomNumber").simple("${random(1,100)}")
    .to("direct:b");
<route>
    <from uri="direct:a"/>
    <setHeader name="randomNumber">
        <simple>${random(1,100)}</simple>
    </setHeader>
    <to uri="direct:b"/>
</route>
- route:
    from:
      uri: direct:a
      steps:
        - setHeader:
            name: randomNumber
            expression:
              simple:
                expression: "${random(1,100)}"
        - to:
            uri: direct:b

See JSONPath for another example.

Setting a header from another header

You can also set a header with the value from another header.

In the example, we set the header foo with the value from an existing header named bar.

  • Java

  • XML

  • YAML

from("direct:a")
    .setHeader("foo", header("bar"))
    .to("direct:b");
<route>
    <from uri="direct:a"/>
    <setHeader name="foo">
        <header>bar</header>
    </setHeader>
    <to uri="direct:b"/>
</route>
- route:
    from:
      uri: direct:a
      steps:
        - setHeader:
            name: foo
            expression:
              header:
                expression: bar
        - to:
            uri: direct:b

If you need to set several headers on the message, see Set Headers.