Apache Camel 3.x to 4.0 Migration Guide

This document is intended to help you migrate your Apache Camel applications from version 3.20 or higher to 4.0. If you are upgrading from an older Camel 3.x release, such as 3.14, then make sure to read the individual Camel 3.x Upgrade Guide to upgrade to the 3.20 release, prior to upgrade to Camel 4.

If you are upgrading Camel 4.x to 4.y then use the Camel 4.x Upgrade Guide.

Java versions

Camel 4 supports Java 17. Support for Java 11 is dropped.

Removed Components

The following components has been removed:

  • camel-activemq

  • camel-any23

  • camel-atmos

  • camel-caffeine-lrucache

  • camel-cdi

  • camel-elasticsearch-rest

  • camel-gora

  • camel-hbase

  • camel-iota

  • camel-ipfs

  • camel-jbpm

  • camel-jclouds

  • camel-johnzon

  • camel-microprofile-metrics

  • camel-milo

  • camel-opentracing

  • camel-optaplanner

  • camel-rabbitmq

  • camel-rest-swagger

  • camel-restdsl-swagger-plugin

  • camel-resteasy

  • camel-spark

  • camel-spring-integration

  • camel-swift

  • camel-swagger-java

  • camel-websocket

  • camel-websocket-jsr356

  • camel-xstream

  • camel-zikin

Logging

Camel 4 has upgraded logging facade API slf4j-api from 1.7 to 2.0.

JUnit 4

All the camel-test modules that were JUnit 4.x based has been removed. All test modules now use JUnit 5.

Component changes

camel-caffeine

The keyType parameter has been removed. The Key for the cache will now be only String type. More information in CAMEL-18877.