Migrating to Red Hat build of Apache Camel for Spring Boot

Fuse applications written in Spring XML or Blueprint XML should be migrated towards an XML-based flavor, and can target either the Spring Boot or the Quarkus runtime with no difference in the migration steps.

Fuse applications written in Java DSL should be migrated towards a Java-based flavor, and can target either the Spring Boot or the Quarkus runtime with no difference in the migration steps.

Consider the following architectural changes when you are migrating your application:

The Java EE move to the Eclipse Foundation and the establishment of Jakarta EE, since Jakarta EE 9, packages used for all EE APIs have changed to jakarta.*

Code snippets in documentation have been updated to use the jakarta.* namespace, but you of course need to take care and review your own applications.

When migrating applications to EE 10, you need to:

Update the existing project’s pom.xml file. In the original Spring Boot application, the pom.xml contained dependencies related to Spring Boot and Apache Camel. Update the dependencies so that the application will run using the latest Camel Spring Boot.

The polled endpoint URI is now stored as property on the Exchange (with key CamelToEndpoint) like all other EIPs. Before the URI was stored as a message header.

The following options in camel-resilience4j was mistakenly not defined as attributes:

These options were not exposed in YAML DSL, and in XML DSL you need to migrate from:

<circuitBreaker>
    <resilience4jConfiguration>
        <timeoutEnabled>true</timeoutEnabled>
        <timeoutDuration>2000</timeoutDuration>
    </resilience4jConfiguration>
...
</circuitBreaker>

<circuitBreaker>
    <resilience4jConfiguration>
        <timeoutEnabled>true</timeoutEnabled>
        <timeoutDuration>2000</timeoutDuration>
    </resilience4jConfiguration>
...
</circuitBreaker>

To use following attributes instead:

<circuitBreaker>
    <resilience4jConfiguration timeoutEnabled="true" timeoutDuration="2000"/>
...
</circuitBreaker>

<circuitBreaker>
    <resilience4jConfiguration timeoutEnabled="true" timeoutDuration="2000"/>
...
</circuitBreaker>

The option camel.health.components-enabled has been renamed to camel.health.producers-enabled.

Some components (in particular AWS) provides also health checks for producers; in Camel 3.x these health checks did not work properly and has been disabled in the source. To continue this behaviour in Camel 4, the producer based health checks are disabled.

Notice that camel-kafka comes with producer based health-check that worked in Camel 3, and therefore this change in Camel 4, means that this health-check is disabled.

You MUST enable producer health-checks globally, such as in application.properties:

camel.health.producers-enabled = true

camel.health.producers-enabled = true

The number of enums for org.apache.camel.Category has been reduced from 83 to 37, which means custom components that are using removed values need to choose one of the remainder values. We have done this to consolidate the number of categories of all components in the Camel community.

This dsl-generator has updated the underlying model classes (apicurio-data-models) from 1.1.27 to 2.0.3.

The camel-atom component has changed the 3rd party atom client from Apache Abdera to RSSReader. This means the feed object is changed from org.apache.abdera.model.Feed to com.apptasticsoftware.rssreader.Item.

The itemPartitionKey has been updated. It’s now a String a not a PartitionKey anymore. More details in CAMEL-19222.

When using the method option to refer to a specific method, and using parameter types and values, such as: "bean:myBean?method=foo(com.foo.MyOrder, true)" then any class types must now be using .class syntax, i.e. com.foo.MyOrder should now be com.foo.MyOrder.class.

"bean:myBean?method=foo(com.foo.MyOrder.class, true)"

"bean:myBean?method=foo(com.foo.MyOrder.class, true)"

This also applies to Java types such as String, int.

"bean:myBean?method=bar(String.class, int.class)"

"bean:myBean?method=bar(String.class, int.class)"

Upgraded from Box Java SDK v2 to v4, which have some method signature changes. The method to get a file thumbnail is no longer available.

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

The underlying hapi-fhir library has been upgraded from 4.2.0 to 6.2.4. Only the Delete API method has changed and now returns ca.uhn.fhir.rest.api.MethodOutcome instead of org.hl7.fhir.instance.model.api.IBaseOperationOutcome. See hapi-fhir for a more detailed list of underlying changes (only the hapi-fhir client is used in Camel).

The API based components camel-google-drive, camel-google-calendar, camel-google-sheets and camel-google-mail has been upgraded from Google Java SDK v1 to v2 and to latest API revisions. The camel-google-drive and camel-google-sheets have some API methods changes, but the others are identical as before.

The component has been upgraded to use Apache HttpComponents v5 which has an impact on how the underlying client is configured. There are 4 different timeouts (connectionRequestTimeout, connectTimeout, soTimeout and responseTimeout) instead of initially 3 (connectionRequestTimeout, connectTimeout and socketTimeout) and the default value of some of them has changed so please refer to the documentation for more details.

Please note that the socketTimeout has been removed from the possible configuration parameters of HttpClient, use responseTimeout instead.

Finally, the option soTimeout along with any parameters included into SocketConfig, need to be prefixed by httpConnection., the rest of the parameters including those defined into HttpClientBuilder and RequestConfig still need to be prefixed by httpClient. like before.

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.

The io.fabric8:kubernetes-client library has been upgraded and some deprecated API usage has been removed. Operations previously prefixed with replace are now prefixed with update.

For example replaceConfigMap is now updateConfigMap, replacePod is now updatePod etc. The corresponding constants in class KubernetesOperations are also renamed. REPLACE_CONFIGMAP_OPERATION is now UPDATE_CONFIGMAP_OPERATION, REPLACE_POD_OPERATION is now UPDATE_POD_OPERATION etc.

The following constants has been moved from BaseMainSupport / Main to MainConstants:

The metrics has been renamed to follow Micrometer naming convention .

The command camel dependencies has been renamed to camel dependency.

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

The camel stop command will now by default stop all running integrations (the option --all has been removed).

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

The camel-openapi-java component has been changed to use io.swagger.v3 libraries instead of io.apicurio.datamodels. As a result, the return type of the public method org.apache.camel.openapi.RestOpenApiReader.read() is now io.swagger.v3.oas.models.OpenAPI instead of io.apicurio.datamodels.openapi.models.OasDocument. When an OpenAPI 2.0 (swagger) specification is parsed, it is automatically upgraded to OpenAPI 3.0.x by the swagger parser. This version also supports OpenAPI 3.1.x specifications. The related spring-boot starter components have been modified to use the new return type.

Property names of blob fields on generated DTOs no longer have 'Url' affixed. For example, the ContentVersionUrl property is now ContentVersion.

The default delay (on slack consumer) is changed from 0.5s to 10s to avoid being rate limited to often by Slack.

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).

When declaring a restConfiguration in a Spring Beans XML file, for example:

<camelContext id="SampleCamel" xmlns="http://camel.apache.org/schema/spring">
    <restConfiguration port="8080" bindingMode="off" scheme="http"
                       contextPath="myapi" apiContextPath="myapi/swagger">
    </restConfiguration>

<camelContext id="SampleCamel" xmlns="http://camel.apache.org/schema/spring">
    <restConfiguration port="8080" bindingMode="off" scheme="http"
                       contextPath="myapi" apiContextPath="myapi/swagger">
    </restConfiguration>

The Camel Spring Boot application does not start due to a circular references error. The RestConfigurationDefinitionAutoConfiguration property is used when you use the Spring properties to configure the REST component. When you define the REST configuration in the XML file, the RestConfigurationDefinitionAutoConfiguration property is not needed. You can disable this property as follows:

@SpringBootApplication(exclude = RestConfigurationDefinitionAutoConfiguration.class)
// load the spring xml file from classpath
@ImportResource("classpath:my-camel.xml")
public class SampleCamelApplication {

@SpringBootApplication(exclude = RestConfigurationDefinitionAutoConfiguration.class)
// load the spring xml file from classpath
@ImportResource("classpath:my-camel.xml")
public class SampleCamelApplication {

Camel now shutdowns a bit later during Spring Boot shutdown. This allows Spring Boot graceful shutdown to complete first (stopping Spring Boot HTTP server gracefully), and then afterward Camel is doing its own Graceful Shutdown.

Technically camel-spring has changed getPhase() from returning Integer.MAX_VALUE to Integer.MAX_VALUE - 2049. This gives room for Spring Boot services to shut down first.

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.

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("...")

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.

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

The component was updated to use Twitter4j version 4.1.2, which has moved the packages used by a few of its classes. If accessing certain twitter-related data, such as the Twit status, you need to update the packages used from twitter4j.Status to twitter4j.v1.Status.

All deprecated components from Camel 2.x are removed in Camel 3.x, including the old camel-http, camel-hdfs, camel-mina, camel-mongodb, camel-netty, camel-netty-http, camel-quartz, camel-restlet and camel-rx components.

Following components are renamed in Camel 3.x.

The mock component has been moved out of camel-core. Because of this a number of methods on its assertion clause builder are removed.

If you are using the activemq-camel component, then you should migrate to use camel-activemq component, where the component name has changed from org.apache.activemq.camel.component.ActiveMQComponent to org.apache.camel.component.activemq.ActiveMQComponent.

The component camel-aws has been split into multiple components:

The camel-cxf JAR has been divided into SOAP vs REST and Spring and non Spring JARs. It is recommended to choose the specific JAR from the following list when migrating from came-cxf.

For example, if you were using CXF for SOAP and with Spring XML, then select camel-cxf-spring-soap and camel-cxf-spring-transport when migrating from camel-cxf.

When using Spring Boot, choose from the following starter when you migrate from camel-cxf-starter to SOAP or REST:

The camel-fhir component has upgraded it’s hapi-fhir dependency to 4.1.0. The default FHIR version has been changed to R4. Therefore, if DSTU3 is desired it has to be explicitly set.

The camel-kafka component has removed the options bridgeEndpoint and circularTopicDetection as this is no longer needed as the component is acting as bridging would work on Camel 2.x. In other words camel-kafka will send messages to the topic from the endpoint uri. To override this use the KafkaConstants.OVERRIDE_TOPIC header with the new topic. See more details in the camel-kafka component documentation.

The camel-telegram component has moved the authorization token from uri-path to a query parameter instead, e.g. migrate

telegram:bots/myTokenHere

telegram:bots/myTokenHere

to

telegram:bots?authorizationToken=myTokenHere

telegram:bots?authorizationToken=myTokenHere

If you run Camel standalone with just camel-core as a dependency, and you want JMX enabled out of the box, then you need to add camel-management as a dependency.

For using ManagedCamelContext you now need to get this extension from CamelContext as follows:

ManagedCamelContext managed = camelContext.getExtension(ManagedCamelContext.class);

ManagedCamelContext managed = camelContext.getExtension(ManagedCamelContext.class);

The XSLT component has moved out of camel-core into camel-xslt and camel-xslt-saxon. The component is separated so camel-xslt is for using the JDK XSTL engine (Xalan), and camel-xslt-saxon is when you use Saxon. This means that you should use xslt and xslt-saxon as component name in your Camel endpoint URIs. If you are using XSLT aggregation strategy, then use org.apache.camel.component.xslt.saxon.XsltSaxonAggregationStrategy for Saxon support. And use org.apache.camel.component.xslt.saxon.XsltSaxonBuilder for Saxon support if using xslt builder. Also notice that allowStax is also only supported in camel-xslt-saxon as this is not supported by the JDK XSLT.

The XML DSL has been changed slightly.

The custom load balancer EIP has changed from <custom> to <customLoadBalancer>

The XMLSecurity data format has renamed the attribute keyOrTrustStoreParametersId to keyOrTrustStoreParametersRef in the <secureXML> tag.

The <zipFile> data format has been renamed to <zipfile>.