Apache Camel 3.x Upgrade Guide

This document is for helping you upgrade your Apache Camel application from Camel 3.x to 3.y. For example if you are upgrading Camel 3.0 to 3.2, then you should follow the guides from both 3.0 to 3.1 and 3.1 to 3.2.

Upgrading Camel 3.20 to 3.21

camel-core

XML parsers & XML transformers has been made more secure by disabling DOCTYPE and/or access to external DTD/Schema.

The org.apache.camel.support.EventNotifierSupport abstract class now implements CamelContextAware.

Tracing

The Tracer and Backlog Tracer no longer includes internal tracing events from routes that was created by Rest DSL or route templates or Kamelets. You can turn this on, by setting traceTemplates=true in the tracer.

The Backlog Tracer has been enhanced and fixed to trace message headers (also streaming types). This means that previously headers of type InputStream was not traced before, but is now included. This could mean that the header stream is positioned at end, and logging the header afterward, may appear as the header value is empty.

UseOriginalMessage / UseOriginalBody

When useOriginalMessage or useOriginalBody is enabled in OnException, OnCompletion or error handlers, then the original message body is defensively copied and if possible converted to StreamCache to ensure the body can be re-read when accessed. Previously the original body was not converted to StreamCache which could lead to the body not able to be read or the stream has been closed.

camel-console

The class org.apache.camel.impl.console.AbstractDevConsole has moved from camel-console to camel-support and moved to package org.apache.camel.support.console.AbstractDevConsole.

Component developers that has plugins for Camel Developer Console, should just use camel-support and camel-util-json as dependencies, and then extend AbstractDevConsole for custom console implementations.

camel-health

The org.apache.camel.health.HealthCheck method isLiveness is now default false instead of true.

Camel provides the CamelContextCheck as both readiness and liveness checks, so there is at least one of each out of the box.

camel-main

The option camel.main.routesReloadRestartDuration has changed its default value from true to false.

camel-http-common

The API in org.apache.camel.http.common.HttpBinding has changed slightly to be more reusable. The parseBody method now takes in HttpServletRequest as input parameter. And all HttpMessage has been changed to generic Message types.

camel-jaxb

When using schema validation, then access to external DTD/Schema is disabled by default. To enable access, then set accessExternalSchemaProtocols=all or specify allowed protocols, such as accessExternalSchemaProtocols=file.

camel-platform-http-vertx

If the route or consumer is suspended then http status 503 is now returned instead of 404.

camel-spring-rabbitmq

The option replyTimeout in camel-spring-rabbitmq has been fixed and the default value from 5 to 30 seconds (this is the default used by Spring).

camel-stax

XML parser in StAXJAXBIteratorExpression has been made more secure by disabling DOCTYPE and/or access to external DTD/Schema.

camel-cm-sms

XML parsers has been made more secure by disabling DOCTYPE and/or access to external DTD/Schema.

camel-schematron

XML parsers has been made more secure by disabling DOCTYPE and/or access to external DTD/Schema.

camel-xmlsecurity

XML parsers has been made more secure by disabling DOCTYPE and/or access to external DTD/Schema.

camel-jbang

The command camel dependencies has been renamed to camel dependency.

In Camel JBang the -dir parameter for init and run goal has been renamed to require 2 dashes --dir like all the other options.

The Placeholders substitutes is changed to use #name instead of $name syntax.

camel-java-joor-dsl

The camel-java-joor-dsl cannot anymore load routes defined in class files as we consider it no more needed, consequently the ability to configure the compile directory and the compile load first flag using the corresponding camel-main properties is no longer possible.

camel-elasticsearch

The certificatePath parameter can now be specified as resource: for user pointing to a local certificate, the file should be now prefixed with file:. It’s also possible to use the classic resource helper prefixes, like classpath, https etc.

camel-rest

The deprecated option componentName was removed. Please use either producerComponentName or consumerComponentName.

Deprecated Components

The following components that had been marked as deprecated, were removed in this release:

camel-dozer
camel-cmis
camel-vertx-kafka

Backlog Tracing

The option backlogTracing=true now automatic enabled the tracer on startup. The previous behavior was surprisingly that the tracer was only made available, and had to be manually enabled afterwards. The old behavior can be archived by setting backlogTracingStandby=true.

Move the following class from org.apache.camel.api.management.mbean.BacklogTracerEventMessage in camel-management-api JAR to org.apache.camel.spi.BacklogTracerEventMessage in camel-api JAR.

Camel Spring Boot

The camel-spring-boot dependency no longer includes camel-spring-xml. To use legacy Spring XML files <beans> with Camel on Spring Boot, then include the camel-spring-boot-xml-starter dependency.

Health Check

The health-check has aligned to be more similar to microprofile-health in the JSon output. Spring Boot now also includes additional data per check, when using full exposure level.

For example as shown below for the context health check:

{
  "status": "UP",
  "components": {
    "camelHealth": {
      "status": "UP",
      "details": {
        "name": "camel-health-check",
        "context": "UP",
        "context.data": {
          "invocation.count": "1",
          "context.phase": "5",
          "invocation.time": "2022-12-21T09:12:03.307871+01:00[Europe/Oslo]",
          "check.group": "camel",
          "context.name": "MyCamel",
          "success.time": "2022-12-21T09:12:03.307871+01:00[Europe/Oslo]",
          "success.count": "1",
          "check.id": "context",
          "context.version": "3.21.0",
          "context.status": "Started",
          "success.start.time": "2022-12-21T09:12:03.307871+01:00[Europe/Oslo]",
          "check.kind": "READINESS",
          "failure.count": "0"
        }
      }
    }
  }
}

camel-micrometer-starter

The uri tags are now static instead of dynamic (by default), as potential too many tags generated due to URI with dynamic values. This can be enabled again by setting camel.metrics.uriTagDynamic=true.

camel-platform-http-starter

If the route or consumer is suspended then http status 503 is now returned instead of 404.

The platform-http-starter has been changed from using camel-servlet to use Spring HTTP server directly. Therefore, all the HTTP endpoints are no longer prefixed with the servlet context-path (default is camel).

For example:

from("platform-http:myservice")
  .to("...")

Then calling myservice would before require to include the context-path, such as http://localhost:8080/camel/myservice. Now the context-path is not in use, and the endpoint can be called with http://localhost:8080/myservice.

The platform-http-starter can also be used with Rest DSL.