Apache Camel 4.x Upgrade Guide

This document is for helping you upgrade your Apache Camel application from Camel 4.x to 4.y. For example, if you are upgrading Camel 4.0 to 4.2, then you should follow the guides from both 4.0 to 4.1 and 4.1 to 4.2.

Upgrading Camel 4.0 to 4.1

camel-api

Added method newInstance(Class<T> type, Class<?> factoryClass, String factoryMethod) to org.apache.camel.spi.Injector.

Added isIgnoreLoadingError and setIgnoreLoadingError methods to org.apache.camel.spi.RoutesLoader, and org.apache.camel.main.RoutesCollector.

Added getDuration method to org.apache.camel.StartupStep.

XML and YAML DSL

Creating beans from script

In route templates (or kamelets), for advanced use cases, you are able to create beans from an inlined script.

The name of the script was defined in type, but has been changed to a new scriptLanguage attribute. And beanType has been removed as you must use type instead.

Before:

  • XML

  • YAML

    <bean name="myBean" type="groovy" beanType="com.foo.MyBean">
        <script>
          <!-- groovy code here to create the bean -->
        </script>
    </bean>
- beans:
  - name: "myClient"
    beanType: "com.foo.MyBean"
    type: "groovy"
    script: |
      # groovy script here

After:

  • XML

  • YAML

    <bean name="myBean" type="com.foo.MyBean"
          scriptLanguage="groovy">
        <script>
          <!-- groovy code here to create the bean -->
        </script>
    </bean>
- beans:
  - name: "myClient"
    type: "com.foo.MyBean"
    scriptLanguage: "groovy"
    script: |
      # groovy script here

camel-management

Dumping routes to JMX no longer includes customId="true" in the XML nodes.

camel-scheduler

The scheduler no longer includes header with the timestamp of when the exchange was fired. This means the exchange by default has no headers, and null body.

The option includeMetadata can be set to true on the endpoint or component level, to turn on these additional metadata headers again.

camel-timer

The timer no longer includes header firedTime with the timestamp of when the exchange was fired. This means the exchange by default has no headers, and null body.

The firedTime header has been renamed to CamelTimerFireTime.

The option includeMetadata can be set to true on the endpoint or component level, to turn on these additional metadata headers again.

camel-aws2-step-functions

The following Message Headers of camel-aws2-step-functions component have been renamed to follow standard camel naming convention.

Old Name New Name

CamelAwsStateMachineOperation

CamelAwsStepFunctionsOperation

CamelAwsStateMachinesMaxResults

CamelAwsStepFunctionsStateMachinesMaxResults

CamelAwsStepFunctionsStateMachineActivityName

CamelAwsStepFunctionsActivityName

CamelAwsStepFunctionsStateMachineActivityArn

CamelAwsStepFunctionsActivityArn

CamelAwsStateMachineActivitiesMaxResults

CamelAwsStepFunctionsActivitiesMaxResults

CamelAwsStateMachineExecutionArn

CamelAwsStepFunctionsExecutionArn

CamelAwsStateMachineExecutionName

CamelAwsStepFunctionsExecutionName

CamelAwsStateMachineExecutionInput

CamelAwsStepFunctionsExecutionInput

CamelAwsStateMachineExecutionTraceHeader

CamelAwsStepFunctionsExecutionTraceHeader

CamelAwsStateMachineExecutionHistoryMaxResults

CamelAwsStepFunctionsExecutionHistoryMaxResults

CamelAwsStateMachineExecutionHistoryIncludeExecutionData

CamelAwsStepFunctionsExecutionHistoryIncludeExecutionData

CamelAwsStateMachineExecutionHistoryReverseOrder

CamelAwsStepFunctionsExecutionHistoryReverseOrder

CamelAwsStateMachineExecutionMaxResults

CamelAwsStepFunctionsExecutionMaxResults

This is applicable only if literal constant headers are used such as CamelAwsStateMachinesMaxResults. If the headers are used from StepFunctions2Constants Interface like StepFunctions2Constants.STATE_MACHINES_MAX_RESULTS , then there is no change;

For Example before

from("direct:listActivities")
  .setHeader("CamelAwsStepFunctionsActivitiesMaxResults",5)
   .to("aws2-step-functions://test?awsSfnClient=#awsSfnClient&operation=listActivities")

Should be changed to

from("direct:listActivities")
  .setHeader("CamelAwsStepFunctionsActivitiesMaxResults",5)
    .to("aws2-step-functions://test?awsSfnClient=#awsSfnClient&operation=listActivities")

camel-aws2-sns

The queueUrl parameter has been replaced by the queueArn parameter

For Example before

from("direct:start")
  .to("aws2-sns://mytopic?subject=mySubject&autoCreateTopic=true&subscribeSNStoSQS=true&queueUrl=https://xxxx")

Should be changed to

from("direct:start")
  .to("aws2-sns://mytopic?subject=mySubject&autoCreateTopic=true&subscribeSNStoSQS=true&queueArn=arn:aws:sqs:xxxxx")

camel-pdf

The Camel-PDF component has been updated to Apache PDFBox 3.0.0, and the font parameter is now defined through the following enum values: COURIER,COURIER_BOLD,COURIER_OBLIQUE,COURIER_BOLD_OBLIQUE, HELVETICA,HELVETICA_BOLD,HELVETICA_OBLIQUE,HELVETICA_BOLD_OBLIQUE,TIMES_ROMAN,TIMES_BOLD,TIMES_ITALIC,TIMES_BOLD_ITALIC,SYMBOL and ZAPF_DINGBATS

camel-jbang

The pipe command has been renamed to script.

The --secrets-refresh and --secret-refresh-providers have been removed, since they were logically incorrect in the export command context. More information at CAMEL-19927 issue.

The generated XML route, created using the command camel init, now uses <camel> as the root tag instead of <routes>.

camel-jetty / camel-servlet / camel-atmosphere-websocket / camel-http-common

By default, stack traces will not be included in HTTP responses, exceptions are muted. Stack traces can be included in HTTP responses by disabling muteException. For example:

from("jetty:http://localhost:{{port}}/myapp/myservice?muteException=false")

When exceptions are muted stack traces may be logged by enabling logException. For example

from("jetty:http://localhost:{{port}}/myapp/myservice?logException=true")

YAML DSL

The kebab-case style schema file, camel-yaml-dsl.json has been removed from the distribution in favor of the camelCase style schema file, camelYamlDsl.json. While the Camel runtime stays supporting kebab-case style also for the moment, it is recommended to migrate to camelCase style. Any tooling should encourage users to use camelCase style.

camel-tracing

The Tag Enum containing constants for tagging spans has been deprecated. Instead, use constants from the TagConstants Class that align to Open Telemetry v1.21.0 semantic conventions.

For example, instead of

span.setTag(Tag.URL_SCHEME, scheme);

use

span.setTag(TagConstants.URL_SCHEME, scheme);

camel-kafka

The default value for sessionTimeoutMs has been updated to 45000 ms, while the default value for consumerRequestTimeoutMs has been updated to 30000. More information in CAMEL-19921 issue.

camel-core, rest

A new rest configuration option, enableNoContentResponse, allows HTTP 204 to be returned with an empty body if a Message contains an empty JSON object or empty XML root object when set to true.

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