Camel Components

Throw Exception

How can I throw an exception

image

Use a special processor to throw an exception.

Options

The Throw Exception 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

message

The message text for the exception to be thrown. Supports simple language expressions.

String

exceptionType

The fully qualified class name of the exception to throw. Used together with message.

String

ref

Reference to an existing exception instance to lookup from the registry and throw.

String

Message Body

The message body at each side of the Throw Exception 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

Fails the exchange with the exception: 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, the sides and the tools that use them are described in Message Body Types.

Exchange properties

The Throw Exception eip has no exchange properties.

Using Throw Exception

In a specific situation we want to fail processing the current message by throwing an exception. In the Content-Based Router below we use throwException in such a case.

  • Java

  • XML

  • YAML

from("direct:start")
    .choice()
        .when(simple("${body} contains 'Hello'")).to("mock:hello")
        .when(simple("${body} contains 'Bye'")).to("mock:bye").throwException(new IllegalArgumentException("Not allowed"))
        .otherwise().to("mock:other")
    .end()
.to("mock:result");

In XML you specify the FQN class name via exceptionType and the message is the caused text to include in the exception.

    <route>
        <from uri="direct:start"/>
        <choice>
            <when>
                <simple>${body} contains 'Hello'</simple>
                <to uri="mock:hello"/>
            </when>
            <when>
                <simple>${body} contains 'Bye'</simple>
                <to uri="mock:bye"/>
                <throwException exceptionType="java.lang.IllegalArgumentException" message="Not Allowed"/>
            </when>
            <otherwise>
                <to uri="mock:other"/>
            </otherwise>
        </choice>
        <to uri="mock:result"/>
    </route>

In YML you specify the FQN class name via exceptionType and the message is the caused text to include in the exception.

- route:
    from:
      uri: direct:start
      steps:
        - choice:
            when:
              - expression:
                  simple:
                    expression: "${body} contains 'Hello'"
                steps:
                  - to:
                      uri: mock:hello
              - expression:
                  simple:
                    expression: "${body} contains 'Bye'"
                steps:
                  - to:
                      uri: mock:bye
                  - throwException:
                      exceptionType: "java.lang.IllegalArgumentException"
                      message: "Not Allowed"
            otherwise:
              steps:
                - to:
                    uri: mock:other
        - to:
            uri: mock:result

See Also

See also the related Stop EIP.