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 4.5 to 4.6

variables

When using variableReceive then the variable is only set if processing the Exchange was completely successfully.

For example, calling a route that fails due to an exception being thrown (even if onException or errorHandler are in use) then the variable is no longer set. Also, if the route is marked for rollback, or to stop continuing routing with .stop().

This is the same logic that the routing engine uses, whether to continue routing the Exchange or not.

camel-core-model

Harmonized model for defining custom beans to be the same for Kamelets and generic beans in XML/YAML DSLs. Before, there used to be three specialized model classes that have been refactored into a single class, offering the same capabilities for configuring beans (constructors, properties, builder classes, init/destroy methods etc.)

XML DSL

When using XML DSL to define properties on <bean> then <property> must now be declared inside <properties>.

YAML DSL

When using YAML DSL to define properties on bean then property has been removed in favour of using properties.

Before:

    beans:
      - name: "myProcessor"
        type: "#class:com.foo.MyClass"
        property:
          - key: "payload"
            value: "test-payload"

After:

    beans:
      - name: "myProcessor"
        type: "#class:com.foo.MyClass"
        properties:
          payload: "test-payload"

Renamed streamCaching to streamCache on the route

Before:

route:
  streamCaching: false
  from:
    uri: "direct:foo"
    steps:
      - to: "mock:bar"

After:

route:
  streamCache: false
  from:
    uri: "direct:foo"
    steps:
      - to: "mock:bar"

camel-elasticsearch

The class org.apache.camel.component.es.aggregation.ElastichsearchBulkRequestAggregationStrategy has been renamed to org.apache.camel.component.es.aggregation.ElasticsearchBulkRequestAggregationStrategy.

camel-rest-openapi

The specifciationUri in the rest-api component has changed from being a java.net.URI to a String type , as it uses Camels ResourceLoader to load from pluggable resources and also more tooling friendly.

The validator using Atlassian swagger-request-validator JAR has been removed, as this library is not JakartaEE compatible, and was causing classloading problems. The validator is now using a similar validation as Rest DSL. However, the validator no longer checks for JSON payloads if any required nodes are missing.

camel-langchain4j-chat

The Camel Langchain4j Chat component name has been changed from camel-langchain-chat`to `camel-langchain4j-chat to adhere to the standardized naming conventions within the LangChain4j ecosystem.

If you are migrating from Camel 4.5, please ensure the following:

Update your maven dependencies, changing from camel-langchain-chat`to `camel-langchain4j-chat
Adjust your endpoints, replacing langchain-chat with langchain4j-chat
Transfer any Camel class references from org.apache.camel.component.chat.ChatLangchain* to org.apache.camel.component.langchain4j.chat.ChatLangchain4j*
Modify the header name The prompt Template from CamelLangChainChatPromptTemplate to CamelLangChain4jChatPromptTemplate

camel-langchain4j-embeddings

The Camel Langchain4j Embeddings component name has been changed from camel-langchain-embedings to camel-langchain4j-embedings to adhere to the standardized naming conventions within the LangChain4j ecosystem.

If you are migrating from Camel 4.5, please ensure the following

Update your maven dependencies, changing from camel-langchain-embedings`to `camel-langchain4j-embedings
Adjust your endpoints, replacing langchain-embedings with langchain4j-embedings
Transfer any Camel class references from org.apache.camel.component.langchain.embeddings.LangChainEmbeddings* to org.apache.camel.component.langchain4j.embeddings.LangChain4jEmbeddings*
Modify the header name The Finish Reason from CamelLangChainEmbeddingsFinishReason to CamelLangChain4jEmbeddingsFinishReason
Modify the header name The Input Token Count from CamelLangChainEmbeddingsInputTokenCount to CamelLangChain4jEmbeddingsInputTokenCount
Modify the header name The Output Token Count from CamelLangChainEmbeddingsOutputTokenCount to CamelLangChain4jEmbeddingsOutputTokenCount
Modify the header name The Total Token Count from CamelLangChainEmbeddingsTotalTokenCount to CamelLangChain4jEmbeddingsTotalTokenCount
Modify the header name A dense vector embedding of a text from CamelLangChainEmbeddingsVector to CamelLangChain4jEmbeddingsVector

camel-platform-http

The PlatformHttpEngine class has changed the createConsumer method to return a org.apache.camel.component.platform.http.spi.PlatformHttpConsumer type, instead of org.apache.camel.Consumer.

camel-platform-http-vertx

The id used for multipart file upload attachments on AttachmentMessage has changed from being the name of the uploaded file, to the value specifed on the name field of the Content-Disposition header sent in the request body.

camel-google-sheets

The option scopes is changed from a Collection to be a String type to make it easy to configure in endpoint URI from all DSLs and tooling. Multiple scopes can be separated by comma.

camel-kafka

The Kafka component now supports custom subscription adapters for applications with very complex subscription logic.

camel-azure-servicebus

The Camel Azure ServiceBus consumer has been refactored to internally use the high-level client instead of the low-level client to more easily support automatic reconnection, competing consumers and high availability, amongst other concerns. The corresponding changes to configuration options are:

The consumer now supports the Competing Consumers EIP. This can be enabled by increasing the newly added maxConcurrentCalls option to a value greater than 1.
The disableAutoComplete option has been removed. Auto-complete is always disabled on the underlying client to ensure that Camel is able to correctly complete, abandon or dead-letter consumed messages as appropriate. The presence of the disableAutoComplete option made little sense, since it is not propagated to the underlying client and enabling this option caused Camel not to take any steps to acknowledge/reject consumed messages. Enabling this option would result in message locks being held indefinitely, which is almost certainly not the desired behaviour.
The high level client always operates in receiveMessages mode (peek mode is not supported), so the consumerOperation option has been removed, along with the ServiceBusConsumerOperationDefinition enum. The associated peekNumMaxMessages option has also been removed.
The receiverAsyncClient option has been replaced with a processorClient option to enable use of a custom-configured client. The parameter type accepted by this option is ServiceBusProcessorClient.
The reconnectDelay option has been removed, since reconnection is now handled internally by the client.

camel-jbang

When running using camel run --source-dir=mydir then Camel JBang will now preload existing files on startup, such as application.properties, and beans and routes (same as if you run with cd mydir; camel run *). This allows configuring settings on Camel on startup, which was not possible beforehand.

The --open-api option has changed from code-first to use the new contract-first Rest DSL style by using the specification file direct as-is.

camel-as2

The camel-as2 component has upgraded HTTP Client 4.x to 5.x, and because of that, there are some options that have changed.

Changes for AS2-MDN asynchronous delivery:

Added an option allowing clients to request an asynchronous receipt by including a 'Receipt-Delivery-Option' header specifying the return URL in the request that is sent to the server.
Added a consumer capable of receiving signed or unsigned asynchronous message disposition notifications sent by the message receiver confirming receipt of the message.

camel-spring-boot

The autoconfiguration of Cluster Service implementations has been moved to dedicated starters:

Type	Starter
Consul	camel-consul-cluster-service-starter
File	camel-file-cluster-service-starter
Infinispan	camel-infinispan-cluster-service-starter
JGroups Lock	camel-jgroups-cluster-service-starter
JGroups Raft	camel-jgroups-raft-cluster-service-starter
Kubernetes	camel-kubernetes-cluster-service-starter
Zookeeper	camel-zookeeper-cluster-service-starter

Type

Starter

Consul

camel-consul-cluster-service-starter

File

camel-file-cluster-service-starter

Infinispan

camel-infinispan-cluster-service-starter

JGroups Lock

camel-jgroups-cluster-service-starter

JGroups Raft

camel-jgroups-raft-cluster-service-starter

Kubernetes

camel-kubernetes-cluster-service-starter

Zookeeper

camel-zookeeper-cluster-service-starter

The Cluster Services are turned on by default unless they are explicitly disabled, for example:

camel.cluster.consul.enabled = false