Apache Camel 4.x Upgrade Guide

Added setLazyBeanStrategy/getLazyBeanStrategy methods to org.apache.camel.spi.CamelBeanPostProcessor.

Renamed Exchange.ACTIVE_SPAN to Exchange.OTEL_ACTIVE_SPAN. Renamed ExchangePropertyKey.ACTIVE_SPAN to ExchangePropertyKey.OTEL_ACTIVE_SPAN.

The queueSize attribute on endpoints which are ManagedBrowseableEndpoint is changed from returning a Long value to an Integer value.

The option useWriter on JSon data format and camel-jackson, has been replaced with combineUnicodeSurrogates as it is intended for 4-bytes characters such as Japanese.

The camel-jms component has changed its default HeaderFilterStrategy to also remove any Camel…​ headers, to act similar to other Camel components. If the old classic behavior is needed then you can configure the JmsComponent to use org.apache.camel.component.jms.ClassicJmsHeaderFilterStrategy as header filter strategy which is the old implementation.

Added int limit as parameter to the browse method in org.apache.camel.component.jms.QueueBrowseStrategy.

The camel-opentelemetry component has had significant bug fixes to handle span activation/deactivations better when Camel route messages synchronously and asynchronously. This component should also work better on Spring Boot.

Upgraded Smooks from 2.0.0-RC4 to 2.0.1 which has API breaking changes in Smooks.

The syntax for retrieving a single field of a secret has been changed.

From this

{{hashicorp:secret:database/username}}

to this

{{hashicorp:secret:database#username}}

You could find more details on CAMEL-21179 issue

The syntax for retrieving a single field of a secret has been changed.

From this

{{aws:database/username}}

to this

{{aws:database#username}}

You could find more details on CAMEL-21179 issue

The syntax for retrieving a single field of a secret has been changed.

From this

{{gcp:database/username}}

to this

{{gcp:database#username}}

You could find more details on CAMEL-21179 issue

The syntax for retrieving a single field of a secret has been changed.

From this

{{azure:database/username}}

to this

{{azure:database#username}}

You could find more details on CAMEL-21179 issue

The camel-aws2-s3 when using headBucket operation will now store the result in a header named CamelAwsS3BucketExists whether the bucket exists or not.

Previously an software.amazon.awssdk.services.s3.model.NoSuchBucketException was thrown, however this would require to use error handling to just check whether the bucket existed. Returning a boolean makes it easier in Camel routes to decide what to do. You may also set the option ignoreBody=true to not change the message body.

The CamelTestSupport class was modified so that the JUnit 5 extension code that was part of the class itself, was moved to a separate class. This is part of the work being done on CAMEL-20837 to modernize the base test code.

In many cases, code should work with no changes provided they are not using any of the API methods that were deprecated in Camel 4.7.0. Additionally, starting with Camel 4.9, we strongly recommend users to avoid relying on single-instance contexts (created via @TestInstance(TestInstance.Lifecycle.PER_CLASS)), as this is considered a deprecated functionality that will be removed in the future. The logs will print a warning message if this behavior is detected.

To avoid split package that can be a problem in environments like OSGI, each camel-debezium module has its own sub package corresponding to the database type. So for example, all the classes of the module camel-debezium-postgres have been moved to a dedicated package which is org.apache.camel.component.debezium.postgres instead of having everything under the root package org.apache.camel.component.debezium.

The following experimental DSL has been removed:

The Camel team is only focusing on Java, XML and YAML DSL.