Apache Camel 3.x Upgrade Guide

The method concurrentTasks on org.apache.camel.support.DefaultScheduledPollConsumerScheduler ` has been renamed to `concurrentConsumers.

The org.apache.camel.cloud.ServiceFilter and org.apache.camel.cloud.ServiceLoadBalancer functional interface methods take the current Exchange as additional parameter to allow for content-based filtering of service candidates. RibbonServiceLoadBalancer has no notion of a current exchange, service filters therefore receive a dummy exchange when used with Ribbon.

The two methods filterTypeInOutputs on org.apache.camel.model.ProcessorDefinitionHelper has changed to return Collection instead of Iterator.

The annotation @Consume has removed its target for field/constructor injection as the @Consume is only to be used on methods. The annotations @Produce and @EndpointInject has removed its target for constructor injection as that is not supported (Camel only does bean post processing)

The option concurrentTasks has been renamed to poolSize to better reflect its purpose. The scheduler has also been fixed to only schedule triggering by one, and not as mistakenly by causing concurrent triggering which causes routing mistakes.

The option configures the pool size of the scheduled thread pool used by the scheduler.

If the scheduler thread is being blocked by anywhere in the downstream routing, and you want the scheduler to schedule with a fixed interval, you can use the Threads EIP as queue for pending tasks.

The camel-jdbc component no longer depends on Spring Framework, instead a new camel-spring-jdbc component has been created. You should use camel-spring-jdbc if you use Spring and need Spring Transaction support. The camel-jdbc is using plain Java JDBC API only.

This component now uses Jackson as the default json parser instead of json-smart.

Usage of JacksonJsonAdapter has been slightly changed.

Component was trying to use JacksonJsonAdapter ahead of automatic conversion of the payload to the InputStream in the previous version. New version tries to convert the payload into InpuStream first. JacksonJsonAdapter is used only if conversion to InputStream is not possible.

Order of the basic payload types (like String, Map, File) has not been changed.

Initialization options for SMN client has slightly changed.

Earlier, the library configured the smn server url based on the region parameter provided in endpoint configurations. Now, it provides more flexibility by allowing camel users by providing fully qualified http url for more customizability.

When endpoint URL is provided, it carries the higher precedence than region based configuration. Any region configuration entered along with endpoint url will be ignored.

The service client is now autowired. No need to set explicitly on your route if it is already in the registry. This is the reason why the autoDiscoverClient option has been removed.

The service client is now autowired. No need to set explicitly on your route if it is already in the registry.

Some of the Camel Spring Boot starters have additional auto configuration options that clashed with component. Therefore those configurations has renamed their configuration keys: