Table of Contents
The Camel CDI component provides auto-configuration for Apache Camel
using CDI as dependency injection framework based
on convention-over-configuration. It auto-detects Camel routes
available in the application and provides beans for common Camel
primitives like Endpoint, FluentProducerTemplate, ProducerTemplate or TypeConverter. It
implements standard Camel bean integration
so that Camel annotations like @Consume, @Produce
and @PropertyInject can be used seamlessly in CDI beans. Besides, it
bridges Camel events (e.g. RouteAddedEvent,
CamelContextStartedEvent, ExchangeCompletedEvent, …) as CDI events
and provides a CDI events endpoint that can be used to consume / produce
CDI events from / to Camel routes.
![]() | Note |
|---|---|
While the Camel CDI component is available as of Camel 2.10, it’s been rewritten in Camel 2.17 to better fit into the CDI programming model. Hence some of the features like the Camel events to CDI events bridge and the CDI events endpoint only apply starting Camel 2.17. |
![]() | Note |
|---|---|
More details on how to test Camel CDI applications are available in Camel CDI testing. |
Camel CDI automatically deploys and configures a CamelContext bean.
That CamelContext bean is automatically instantiated, configured and
started (resp. stopped) when the CDI container initializes (resp. shuts
down). It can be injected in the application, e.g.:
@Inject
CamelContext context;That default CamelContext bean is qualified with the
built-in @Default qualifier, is scoped @ApplicationScoped and is of
type DefaultCamelContext.
Note that this bean can be customized programmatically and other Camel context beans can be deployed in the application as well.
Camel CDI automatically collects all the RoutesBuilder beans in the
application, instantiates and add them to the CamelContext bean
instance when the CDI container initializes. For example, adding a Camel
route is as simple as declaring a class, e.g.:
class MyRouteBean extends RouteBuilder {
@Override
public void configure() {
from("jms:invoices").to("file:/invoices");
}
}Note that you can declare as many RoutesBuilder beans as you want.
Besides, RouteContainer beans are also automatically collected,
instantiated and added to the CamelContext bean instance managed by
Camel CDI when the container initializes.
Camel CDI provides beans for common Camel primitives that can be injected in any CDI beans, e.g.:
@Inject @Uri("direct:inbound") ProducerTemplate producerTemplate; @Inject @Uri("direct:inbound") FluentProducerTemplate fluentProducerTemplate; @Inject MockEndpoint outbound; // URI defaults to the member name, i.e. mock:outbound @Inject @Uri("direct:inbound") Endpoint endpoint; @Inject TypeConverter converter;
If you just want to change the name of the default CamelContext bean,
you can used the @ContextName qualifier provided by Camel CDI, e.g.:
@ContextName("camel-context") class MyRouteBean extends RouteBuilder { @Override public void configure() { from("jms:invoices").to("file:/invoices"); } }
Else, if more customization is needed, any CamelContext class can be
used to declare a custom Camel context bean. Then,
the @PostConstruct and @PreDestroy lifecycle callbacks can be done
to do the customization, e.g.:
@ApplicationScoped class CustomCamelContext extends DefaultCamelContext { @PostConstruct void customize() { // Set the Camel context name setName("custom"); // Disable JMX disableJMX(); } @PreDestroy void cleanUp() { // ... } }
Producer and disposer methods can also be used as well to customize the Camel context bean, e.g.:
class CamelContextFactory {
@Produces
@ApplicationScoped
CamelContext customize() {
DefaultCamelContext context = new DefaultCamelContext();
context.setName("custom");
return context;
}
void cleanUp(@Disposes CamelContext context) {
// ...
}
}Similarly, producer fields can be used, e.g.:
@Produces @ApplicationScoped CamelContext context = new CustomCamelContext(); class CustomCamelContext extends DefaultCamelContext { CustomCamelContext() { setName("custom"); } }
This pattern can be used for example to avoid having the Camel context
routes started automatically when the container initializes by calling
the setAutoStartup method, e.g.:
@ApplicationScoped class ManualStartupCamelContext extends DefaultCamelContext { @PostConstruct void manual() { setAutoStartup(false); } }
Any number of CamelContext beans can actually be declared in the
application as documented above. In that case, the CDI qualifiers
declared on these CamelContext beans are used to bind the Camel routes
and other Camel primitives to the corresponding Camel contexts. From
example, if the following beans get declared:
@ApplicationScoped @ContextName("foo") class FooCamelContext extends DefaultCamelContext { } @ApplicationScoped @BarContextQualifier class BarCamelContext extends DefaultCamelContext { } @ContextName("foo") class RouteAddedToFooCamelContext extends RouteBuilder { @Override public void configure() { // ... } } @BarContextQualifier class RouteAddedToBarCamelContext extends RouteBuilder { @Override public void configure() { // ... } } @ContextName("baz") class RouteAddedToBazCamelContext extends RouteBuilder { @Override public void configure() { // ... } } @MyOtherQualifier class RouteNotAddedToAnyCamelContext extends RouteBuilder { @Override public void configure() { // ... } }
The RoutesBuilder beans qualified with @ContextName are
automatically added to the corresponding CamelContext beans by Camel
CDI. If no such CamelContext bean exists, it gets automatically
created, as for the RouteAddedToBazCamelContext bean. Note this only
happens for the @ContextName qualifier provided by Camel CDI. Hence
the RouteNotAddedToAnyCamelContext bean qualified with the
user-defined @MyOtherQualifier qualifier does not get added to any
Camel contexts. That may be useful, for example, for Camel routes that
may be required to be added later during the application execution.
![]() | Note |
|---|---|
Since Camel version 2.17.0, Camel CDI is capable of managing any kind of
|
The CDI qualifiers declared on the CamelContext beans are also used to
bind the corresponding Camel primitives, e.g.:
@Inject @ContextName("foo") @Uri("direct:inbound") ProducerTemplate producerTemplate; @Inject @ContextName("foo") @Uri("direct:inbound") FluentProducerTemplate fluentProducerTemplate; @Inject @BarContextQualifier MockEndpoint outbound; // URI defaults to the member name, i.e. mock:outbound @Inject @ContextName("baz") @Uri("direct:inbound") Endpoint endpoint;
To configure the sourcing of the configuration properties used by Camel
to resolve properties placeholders, you can declare
a PropertiesComponent bean qualified with @Named("properties"),
e.g.:
@Produces @ApplicationScoped @Named("properties") PropertiesComponent propertiesComponent() { Properties properties = new Properties(); properties.put("property", "value"); PropertiesComponent component = new PropertiesComponent(); component.setInitialProperties(properties); component.setLocation("classpath:placeholder.properties"); return component; }
If you want to
use DeltaSpike
configuration mechanism you can declare the
following PropertiesComponent bean:
@Produces @ApplicationScoped @Named("properties") PropertiesComponent properties(PropertiesParser parser) { PropertiesComponent component = new PropertiesComponent(); component.setPropertiesParser(parser); return component; } // PropertiesParser bean that uses DeltaSpike to resolve properties static class DeltaSpikeParser extends DefaultPropertiesParser { @Override public String parseProperty(String key, String value, Properties properties) { return ConfigResolver.getPropertyValue(key); } }
You can see the camel-example-cdi-properties example for a working
example of a Camel CDI application using DeltaSpike configuration
mechanism.
CDI beans annotated with the @Converter annotation are automatically
registered into the deployed Camel contexts, e.g.:
@Converter public class MyTypeConverter { @Converter public Output convert(Input input) { //... } }
Note that CDI injection is supported within the type converters.
Table of Contents
As part of the Camel bean integration, Camel comes with a set of annotations that are seamlessly supported by Camel CDI. So you can use any of these annotations in your CDI beans, e.g.:
| Camel annotation | CDI equivalent | |
|---|---|---|
Configuration property | @PropertyInject("key")
String value; | If using DeltaSpike configuration mechanism: @Inject @ConfigProperty(name = "key") String value; See configuration properties for more details. |
Producer template injection (default Camel context) | @Produce(uri = "mock:outbound") ProducerTemplate producer; @Produce(uri = "mock:outbound") FluentProducerTemplate producer; | @Inject @Uri("direct:outbound") ProducerTemplate producer; @Produce(uri = "direct:outbound") FluentProducerTemplate producer; |
Endpoint injection (default Camel context) | @EndpointInject(uri = "direct:inbound")
Endpoint endpoint; | @Inject @Uri("direct:inbound") Endpoint endpoint; |
Endpoint injection (Camel context by name) | @EndpointInject(uri = "direct:inbound",
context = "foo")
Endpoint contextEndpoint; | @Inject @ContextName("foo") @Uri("direct:inbound") Endpoint contextEndpoint; |
Bean injection (by type) | @BeanInject
MyBean bean; | @Inject
MyBean bean; |
Bean injection (by name) | @BeanInject("foo")
MyBean bean; | @Inject @Named("foo") MyBean bean; |
POJO consuming | @Consume(uri = "seda:inbound") void consume(@Body String body) { //... } |
|
You can refer to CDI beans, either by type or name, From the Camel DSL, e.g. with the Java Camel DSL:
class MyBean {
//...
}
from("direct:inbound").bean(MyBean.class);Or to lookup a CDI bean by name from the Java DSL:
@Named("foo")
class MyNamedBean {
//...
}
from("direct:inbound").bean("foo");When configuring endpoints using the URI syntax you can refer to beans
in the Registry using the # notation. If the URI
parameter value starts with a # sign then Camel CDI will lookup for a
bean of the given type by name, e.g.:
from("jms:queue:{{destination}}?transacted=true&transactionManager=#jtaTransactionManager").to("...");Having the following CDI bean qualified
with @Named("jtaTransactionManager"):
@Produces @Named("jtaTransactionManager") PlatformTransactionManager createTransactionManager(TransactionManager transactionManager, UserTransaction userTransaction) { JtaTransactionManager jtaTransactionManager = new JtaTransactionManager(); jtaTransactionManager.setUserTransaction(userTransaction); jtaTransactionManager.setTransactionManager(transactionManager); jtaTransactionManager.afterPropertiesSet(); return jtaTransactionManager; }
Available as of Camel 2.17
Camel provides a set of management events that can be subscribed to for listening to Camel context, service, route and exchange events. Camel CDI seamlessly translates these Camel events into CDI events that can be observed using CDI observer methods, e.g.:
void onContextStarting(@Observes CamelContextStartingEvent event) {
// Called before the default Camel context is about to start
}As of Camel 2.18, it is possible to observe events for a particular route (RouteAddedEvent,
RouteStartedEvent, RouteStoppedEvent and RouteRemovedEvent) should it have
an explicit defined, e.g.:
from("...").routeId("foo").to("...");
void onRouteStarted(@Observes @Named("foo") RouteStartedEvent event) {
// Called after the route "foo" has started
}When multiple Camel contexts exist in the CDI container, the Camel
context bean qualifiers, like @ContextName, can be used to refine the
observer method resolution to a particular Camel context as specified
in observer
resolution, e.g.:
void onRouteStarted(@Observes @ContextName("foo") RouteStartedEvent event) { // Called after the route 'event.getRoute()' for the Camel context 'foo' has started } void onContextStarted(@Observes @Manual CamelContextStartedEvent event) { // Called after the the Camel context qualified with '@Manual' has started }
Similarly, the @Default qualifier can be used to observe Camel events
for the default Camel context if multiples contexts exist, e.g.:
void onExchangeCompleted(@Observes @Default ExchangeCompletedEvent event) { // Called after the exchange 'event.getExchange()' processing has completed }
In that example, if no qualifier is specified, the @Any qualifier is
implicitly assumed, so that corresponding events for all the Camel
contexts get received.
Note that the support for Camel events translation into CDI events is only activated if observer methods listening for Camel events are detected in the deployment, and that per Camel context.
Available as of Camel 2.17
The CDI event endpoint bridges the CDI events with the Camel routes so that CDI events can be seamlessly observed / consumed (resp. produced / fired) from Camel consumers (resp. by Camel producers).
The CdiEventEndpoint<T> bean provided by Camel CDI can be used to
observe / consume CDI events whose event type is T, for example:
@Inject
CdiEventEndpoint<String> cdiEventEndpoint;
from(cdiEventEndpoint).log("CDI event received: ${body}");This is equivalent to writing:
@Inject @Uri("direct:event") ProducerTemplate producer; void observeCdiEvents(@Observes String event) { producer.sendBody(event); } from("direct:event").log("CDI event received: ${body}");
Conversely, the CdiEventEndpoint<T> bean can be used to produce / fire
CDI events whose event type is T, for example:
@Inject
CdiEventEndpoint<String> cdiEventEndpoint;
from("direct:event").to(cdiEventEndpoint).log("CDI event sent: ${body}");This is equivalent to writing:
@Inject Event<String> event; from("direct:event").process(new Processor() { @Override public void process(Exchange exchange) { event.fire(exchange.getBody(String.class)); } }).log("CDI event sent: ${body}");
Or using a Java 8 lambda expression:
@Inject
Event<String> event;
from("direct:event")
.process(exchange -> event.fire(exchange.getIn().getBody(String.class)))
.log("CDI event sent: ${body}");The type variable T (resp. the qualifiers) of a
particular CdiEventEndpoint<T> injection point are automatically
translated into the parameterized event type (resp. into the event
qualifiers) e.g.:
@Inject @FooQualifier CdiEventEndpoint<List<String>> cdiEventEndpoint; from("direct:event").to(cdiEventEndpoint); void observeCdiEvents(@Observes @FooQualifier List<String> event) { logger.info("CDI event: {}", event); }
When multiple Camel contexts exist in the CDI container, the Camel
context bean qualifiers, like @ContextName, can be used to qualify
the CdiEventEndpoint<T> injection points, e.g.:
@Inject @ContextName("foo") CdiEventEndpoint<List<String>> cdiEventEndpoint; // Only observes / consumes events having the @ContextName("foo") qualifier from(cdiEventEndpoint).log("Camel context (foo) > CDI event received: ${body}"); // Produces / fires events with the @ContextName("foo") qualifier from("...").to(cdiEventEndpoint); void observeCdiEvents(@Observes @ContextName("foo") List<String> event) { logger.info("Camel context (foo) > CDI event: {}", event); }
Note that the CDI event Camel endpoint dynamically adds an observer method for each unique combination of event type and event qualifiers and solely relies on the container typesafe observer resolution, which leads to an implementation as efficient as possible.
Besides, as the impedance between the typesafe nature of CDI and the dynamic nature of the Camel component model is quite high, it is not possible to create an instance of the CDI event Camel endpoint via URIs. Indeed, the URI format for the CDI event component is:
cdi-event://PayloadType<T1,...,Tn>[?qualifiers=QualifierType1[,...[,QualifierTypeN]...]]
With the authority PayloadType (resp. the QualifierType) being the
URI escaped fully qualified name of the payload (resp. qualifier) raw
type followed by the type parameters section delimited by angle brackets
for payload parameterized type. Which leads to unfriendly URIs,
e.g.:
cdi-event://org.apache.camel.cdi.example.EventPayload%3Cjava.lang.Integer%3E?qualifiers=org.apache.camel.cdi.example.FooQualifier%2Corg.apache.camel.cdi.example.BarQualifier
But more fundamentally, that would prevent efficient binding between the endpoint instances and the observer methods as the CDI container doesn’t have any ways of discovering the Camel context model during the deployment phase.
Available as of Camel 2.18
While CDI favors a typesafe dependency injection mechanism, it may be useful to reuse existing Camel XML configuration files into a Camel CDI application. In other use cases, it might be handy to rely on the Camel XML DSL to configure its Camel context(s).
You can use the @ImportResource annotation that’s provided by Camel
CDI on any CDI beans and Camel CDI will automatically load the Camel XML
configuration at the specified locations, e.g.:
@ImportResource("camel-context.xml")
class MyBean {
}Camel CDI will load the resources at the specified locations from the classpath (other protocols may be added in the future).
Every CamelContext elements and other Camel primitives from the
imported resources are automatically deployed as CDI beans during the
container bootstrap so that they benefit from the auto-configuration
provided by Camel CDI and become available for injection at runtime. If
such an element has an explicit id attribute set, the corresponding
CDI bean is qualified with the @Named qualifier, e.g., given the
following Camel XML configuration:
<camelContext id="foo"> <endpoint id="bar" uri="seda:inbound"> <property key="queue" value="#queue"/> <property key="concurrentConsumers" value="10"/> </endpoint> <camelContext/>
The corresponding CDI beans are automatically deployed and can be injected, e.g.:
@Inject @ContextName("foo") CamelContext context; @Inject @Named("bar") Endpoint endpoint;
Note that the CamelContext beans are automatically qualified with both
the @Named and @ContextName qualifiers. If the
imported CamelContext element doesn’t have an id attribute, the
corresponding bean is deployed with the built-in @Default qualifier.
Conversely, CDI beans deployed in the application can be referred to
from the Camel XML configuration, usually using the ref attribute,
e.g., given the following bean declared:
@Produces @Named("baz") Processor processor = exchange -> exchange.getIn().setHeader("qux", "quux");
A reference to that bean can be declared in the imported Camel XML configuration, e.g.:
<camelContext id="foo"> <route> <from uri="..."/> <process ref="baz"/> </route> <camelContext/>
Available as of Camel 2.17
The Camel context beans are automatically adapted by Camel CDI so that
they are registered as OSGi services and the various resolvers
(like ComponentResolver and DataFormatResolver) integrate with the
OSGi registry. That means that the Karaf Camel commands
can be used to operate the Camel contexts auto-configured by Camel CDI,
e.g.:
1 karaf@root()> camel:context-list 2 Context Status Total # Failed # Inflight # Uptime 3 ------- ------ ------- -------- ---------- ------ 4 camel-cdi Started 1 0 0 1 minute
See the camel-example-cdi-osgi example for a working example of the
Camel CDI OSGi integration.
While the CDI programmatic model favors a typesafe resolution mechanism that occurs at application initialization time, it is possible to perform dynamic / lazy injection later during the application execution using the programmatic lookup mechanism.
Camel CDI provides for convenience the annotation literals corresponding to the
CDI qualifiers that you can use for standard injection of Camel primitives.
These annotation literals can be used in conjunction with the javax.enterprise.inject.Instance
interface which is the CDI entry point to perform lazy injection / programmatic lookup.
For example, you can use the provided annotation literal for the @Uri qualifier
to lazily lookup for Camel primitives, e.g. for ProducerTemplate beans:
@Any @Inject Instance<ProducerTemplate> producers; ProducerTemplate inbound = producers .select(Uri.Literal.of("direct:inbound")) .get();
Or for Endpoint beans, e.g.:
@Any @Inject Instance<Endpoint> endpoints; MockEndpoint outbound = endpoints .select(MockEndpoint.class, Uri.Literal.of("mock:outbound")) .get();
Similarly, you can use the provided annotation literal for
the @ContextName qualifier to lazily lookup for CamelContext
beans, e.g.:
@Any @Inject Instance<CamelContext> contexts; CamelContext context = contexts .select(ContextName.Literal.of("foo")) .get();
You can also refined the selection based on the Camel context type, e.g.:
@Any @Inject Instance<CamelContext> contexts; // Refine the selection by type Instance<DefaultCamelContext> context = contexts.select(DefaultCamelContext.class); // Check if such a bean exists then retrieve a reference if (!context.isUnsatisfied()) context.get();
Or even iterate over a selection of Camel contexts, e.g.:
@Any @Inject Instance<CamelContext> contexts; for (CamelContext context : contexts) context.setUseBreadcrumb(true);
Among the available Camel Maven
archetypes, you can use the provided camel-archetype-cdi to generate
a Camel CDI Maven project, e.g.:
mvn archetype:generate -DarchetypeGroupId=org.apache.camel.archetypes -DarchetypeArtifactId=camel-archetype-cdi
The Camel CDI component is compatible with any CDI 1.0, CDI 1.1 and CDI 1.2 compliant runtime. It’s been successfully tested against the following runtimes:
| Container | Version | Runtime |
|---|---|---|
Weld SE |
| CDI 1.0 / Java SE 7 |
OpenWebBeans |
| CDI 1.0 / Java SE 7 |
Weld SE |
| CDI 1.2 / Java SE 7 |
OpenWebBeans |
| CDI 1.2 / Java SE 7 |
WildFly |
| CDI 1.2 / Java EE 7 |
WildFly |
| CDI 1.2 / Java EE 7 |
WildFly |
| CDI 1.2 / Java EE 7 |
Karaf |
| CDI 1.2 / OSGi 4 / PAX CDI |
Karaf |
| CDI 1.2 / OSGi 5 / PAX CDI |
Karaf |
| CDI 1.2 / OSGi 6 / PAX CDI |
The following examples are available in the examples directory of the
Camel project:
| Example | Description |
|---|---|
| Illustrates how to work with Camel using CDI to configure components, endpoints and beans |
| Illustrates the integration between Camel, CDI and Kubernetes |
| Illustrates the integration between Camel, Dropwizard Metrics and CDI |
| Illustrates the integration between Camel, DeltaSpike and CDI for configuration properties |
| A CDI application using the SJMS component that can be executed inside an OSGi container using PAX CDI |
| Illustrates the Camel REST DSL being used in a Web application that uses CDI as dependency injection framework |
| Demonstrates the testing features that are provided as part of the integration between Camel and CDI |
| Illustrates the use of Camel XML configuration files into a Camel CDI application |
| An example using REST DSL and Swagger Java with CDI |
| The Widget and Gadget use-case from the EIP book implemented in Java with CDI dependency Injection |
The Chronicle Engine component has no options.
The Chronicle Engine component supports 13 endpoint options which are listed below:
{% raw %}
| Name | Group | Default | Java Type | Description |
|---|---|---|---|---|
addresses | common |
| Required Engine addresses. Multiple addresses can be separated by comman. | |
path | common |
| Required Engine path | |
action | common |
| The default action to perform valid values are: - PUBLISH - PPUBLISH_AND_INDEX - PPUT - PGET_AND_PUT - PPUT_ALL - PPUT_IF_ABSENT - PGET - PGET_AND_REMOVE - PREMOVE - PIS_EMPTY - PSIZE | |
filteredMapEvents | common |
| A comma separated list of Map event type to filer valid values are: INSERT UPDATE REMOVE. | |
persistent | common |
|
| Enable/disable data persistence |
subscribeMapEvents | common |
|
| Set if consumer should subscribe to Map events default true. |
subscribeTopicEvents | common |
|
| Set if consumer should subscribe to TopicEventsd efault false. |
subscribeTopologicalEvents | common |
|
| Set if consumer should subscribe to TopologicalEventsd efault false. |
wireType | common |
|
| The Wire type to use default to binary wire. |
bridgeErrorHandler | consumer |
|
| Allows for bridging the consumer to the Camel routing Error Handler which mean any exceptions occurred while the consumer is trying to pickup incoming messages or the likes will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions that will be logged at WARN/ERROR level and ignored. |
exceptionHandler | consumer (advanced) |
| To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this options is not in use. By default the consumer will deal with exceptions that will be logged at WARN/ERROR level and ignored. | |
exchangePattern | consumer (advanced) |
| Sets the exchange pattern when the consumer creates an exchange. | |
synchronous | advanced |
|
| Sets whether synchronous processing should be strictly used or Camel is allowed to use asynchronous processing (if supported). |
{% endraw %}