Camel Components

Switch

Since Camel 4.23

Switch selects one destination from a table declared by the route author. The selector can use any Camel expression language. Its result selects a case; it cannot supply a new endpoint URI.

Use Switch for literal value dispatch. Use Choice for predicates, ranges, overlapping conditions, or nested processing steps. A case can send to a direct: route when more processing is needed. Use To D when the endpoint URI itself must be calculated dynamically.

Switch has no inline processing steps: each case sends to one endpoint. Keep each branch in its own route, linked through Direct or SEDA, so it can be read and tested separately. For predicates, ranges, or inline processing steps, use Choice.

Options

The Switch 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

selector

Required Expression evaluated once per entry. Returns a scalar value to match against the literal cases.

ExpressionSubElementDefinition

case

Literal cases. Duplicate values are rejected at startup, ignoring case.

List

otherwise

Fixed fallback URI for null or unmatched selector results. Without a fallback processing continues.

SwitchOtherwiseDefinition

Scalar selectors

The selector is evaluated once on each entry. Scalar results are converted to strings and matched case-insensitively using the English locale. An empty string is a valid literal. An asterisk is literal, not a wildcard. Duplicate normalized values are rejected at startup.

Map, collection and array results are rejected with an IllegalArgumentException. They follow normal Camel error handling and do not select otherwise.

Route from a header

This route reads the department header. The body is passed unchanged to the selected destination. Each case has a separate direct: handling route. Replace the logging steps with the application’s processing. The examples on this page are independent; load one at a time.

  • Java

  • XML

  • YAML

from("direct:tickets")
    .doSwitch(header("department"))
        .doCase("billing", "direct:billing")
        .doCase("technical", "direct:technical")
        .otherwise("direct:review")
    .end();

from("direct:billing").log("Billing: ${body}");
from("direct:technical").log("Technical: ${body}");
from("direct:review").log("Review: ${body}");
<routes xmlns="http://camel.apache.org/schema/xml-io">
    <route>
        <from uri="direct:tickets"/>
        <switch>
            <selector><header>department</header></selector>
            <case value="billing" uri="direct:billing"/>
            <case value="technical" uri="direct:technical"/>
            <otherwise uri="direct:review"/>
        </switch>
    </route>
    <route><from uri="direct:billing"/><log message="Billing: ${body}"/></route>
    <route><from uri="direct:technical"/><log message="Technical: ${body}"/></route>
    <route><from uri="direct:review"/><log message="Review: ${body}"/></route>
</routes>
- route:
    from:
      uri: direct:tickets
      steps:
        - switch:
            selector:
              header:
                expression: department
            case:
              - value: billing
                uri: direct:billing
              - value: technical
                uri: direct:technical
            otherwise:
              uri: direct:review

- route:
    from:
      uri: direct:billing
      steps:
        - log: "Billing: ${body}"
- route:
    from:
      uri: direct:technical
      steps:
        - log: "Technical: ${body}"
- route:
    from:
      uri: direct:review
      steps:
        - log: "Review: ${body}"

Send a message to any of these equivalent routes with a ProducerTemplate:

template.sendBodyAndHeader("direct:tickets", "Please check this invoice",
    "department", "BILLING");
Header value Destination

billing or BILLING

direct:billing

technical

direct:technical

sales or an absent header

direct:review

A null or unmatched result uses otherwise. Without otherwise, the exchange continues after Switch. Selector failures follow normal Camel error handling and never select the fallback. Streams are reset after selector evaluation when stream caching is enabled. Loops and retries that enter Switch again evaluate the selector again; results are not cached across entries.

Use the Endpoint DSL

With an EndpointRouteBuilder, cases and the fallback also accept endpoint builders. Both case forms support endpoint options, including object-valued options, just like to(…​):

from(direct("tickets"))
    .doSwitch(header("department"))
        .doCase("billing", direct("billing"))
        .doCase("technical").to(direct("technical"))
        .otherwise(direct("review"))
    .end();

Classify and route with Semantic

A Semantic choice question returns a category string that Switch can match against its literal cases. Configure camel-semantic and a provider as described in the language documentation. This example uses one reference, ref:department, to evaluate the message body once and route the result. Load it alongside the direct:billing, direct:technical, and direct:review handling routes shown above.

- semantic:
    question:
      department:
        type: choice
        instructions: Which department should handle this message?
        criteria:
          billing: Invoices, payments and refunds
          technical: Bugs, outages and technical problems
          other: Any other request
- route:
    from:
      uri: direct:classify
      steps:
        - switch:
            selector:
              language:
                language: semantic
                expression: ref:department
            case:
              - value: billing
                uri: direct:billing
              - value: technical
                uri: direct:technical
            otherwise:
              uri: direct:review

Destinations and management

Case and fallback URIs support property placeholders resolved at startup. Simple expressions in URIs are rejected. In YAML, both cases and otherwise accept uri plus parameters:

case:
  - value: orders
    uri: kafka
    parameters:
      topic: orders
otherwise:
  uri: direct
  parameters:
    name: review

The route-structure developer console shows the destination of each case, such as case[billing → direct:billing], and identifies the fallback as otherwise[direct:review]. Sensitive URI parameters are masked in these labels.

Each case has an identity for tracing, debugging and management. The Switch MBean’s extendedInformation table reports case IDs, literal values, destination URIs and selection counts. URIs are masked when management masking is enabled (the default). These counts indicate case selection, not successful delivery. UnmatchedCount also records unmatched results when no fallback is configured.