Camel Components

Set Headers

The SetHeaders EIP is used for setting multiple message headers at the same time.

Options

The Set Headers 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

headers

Required Contains the headers to be set.

List

Message Body

The message body at each side of the Set Headers 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 headers: 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 Headers eip has no exchange properties.

Using Set Headers

The following example shows how to set multiple headers in a Camel route using Java, XML or YAML. Note that the syntax is slightly different in each case.

  • Java

  • XML

  • YAML

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

For example, the header values are constants.

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

  • Java

  • XML

  • YAML

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

Setting a header from another header

You can also set several headers where later ones depend on earlier ones.

In the example, we first set the header foo to the body and then set bar based on comparing foo with a value.

  • Java

  • XML

  • YAML

from("direct:a")
    .setHeaders("foo", simple("${body}"), "bar", simple("${header.foo} > 10", Boolean.class))
    .to("direct:b");
<route>
    <from uri="direct:a"/>
    <setHeaders>
        <setHeader name="foo">
            <simple>${body}</simple>
        </setHeader>
        <setHeader name="bar">
            <simple resultType="java.lang.Boolean">${header.foo} > 10</simple>
        </setHeader>
    </setHeaders>
    <to uri="direct:b"/>
</route>
- route:
    from:
      uri: direct:a
      steps:
        - setHeaders:
            headers:
              - name: foo
                expression:
                  simple:
                    expression: "${body}"
              - name: bar
                expression:
                  simple:
                    expression: "${header.foo} > 10"
                    resultType: boolean
        - to:
            uri: direct:b

Using a Map with Java DSL

It’s also possible to build a Map and pass it as the single argument to setHeaders(). If the order in which the headers should be set is important, use a LinkedHashMap.

Java-only: using a LinkedHashMap to set headers in order
Map<String, Expression> headerMap = new java.util.LinkedHashMap<>();
headerMap.put("foo", ConstantLanguage.constant("ABC"));
headerMap.put("bar", ConstantLanguage.constant("XYZ"));

from("direct:startMap")
    .setHeaders(headerMap)
    .to("direct:b");

If the ordering is not critical, then Map.of(name1, expr1, name2, expr2…​) can be used.

Java-only: using Map.of for unordered headers
from("direct:startMap")
    .setHeaders(Map.of("foo", "ABC", "bar", "XYZ"))
    .to("direct:b");