[[cdi-component]]
== Camel CDI

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.

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.

More details on how to test Camel CDI applications are available in
Camel CDI testing.

[CAUTION]
====
camel-cdi is deprecated in OSGi and not supported. Use OSGi Blueprint if using Camel with OSGi.
====

=== Auto-configured Camel context

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.:

[source,java]
----
@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.

=== Auto-detecting Camel routes

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.:

[source,java]
----
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.

*Available as of Camel 2.19*

In some situations, it may be necessary to disable the auto-configuration of the `RouteBuilder` and `RouteContainer` beans. That can be achieved by observing for the `CdiCamelConfiguration` event, e.g.:

[source,java]
----
static void configuration(@Observes CdiCamelConfiguration configuration) {
    configuration.autoConfigureRoutes(false);
}
----

Similarly, it is possible to deactivate the automatic starting of the configured `CamelContext` beans, e.g.:

[source,java]
----
static void configuration(@Observes CdiCamelConfiguration configuration) {
    configuration.autoStartContexts(false);
}
----

=== Auto-configured Camel primitives

Camel CDI provides beans for common Camel primitives that can be
injected in any CDI beans, e.g.:

[source,java]
----
@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;
----

=== Camel context configuration

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.:

[source,java]
----
@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.:

[source,java]
----
@ApplicationScoped
class CustomCamelContext extends DefaultCamelContext {

    @PostConstruct
    void customize() {
        // Set the Camel context name
        setName("custom");
        // Disable JMX
        disableJMX();
    }

    @PreDestroy
    void cleanUp() {
        // ...
    }
}
----

link:http://docs.jboss.org/cdi/spec/1.2/cdi-spec.html#producer_method[Producer]
and link:http://docs.jboss.org/cdi/spec/1.2/cdi-spec.html#disposer_method[disposer]
methods can also be used as well to customize the Camel context bean, e.g.:

[source,java]
----
class CamelContextFactory {

    @Produces
    @ApplicationScoped
    CamelContext customize() {
        DefaultCamelContext context = new DefaultCamelContext();
        context.setName("custom");
        return context;
    }

    void cleanUp(@Disposes CamelContext context) {
        // ...
    }
}
----

Similarly, link:http://docs.jboss.org/cdi/spec/1.2/cdi-spec.html#producer_field[producer
fields] can be used, e.g.:

[source,java]
----
@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.:

[source,java]
----
@ApplicationScoped
class ManualStartupCamelContext extends DefaultCamelContext {

    @PostConstruct
    void manual() {
        setAutoStartup(false);
    }
}
----

=== Multiple Camel contexts

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:

[source,java]
----
@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
`CamelContext` beans (e.g. `DefaultCamelContext`). In previous versions,
it is only capable of managing beans of type `CdiCamelContext` so it is
required to extend it.

The CDI qualifiers declared on the `CamelContext` beans are also used to
bind the corresponding Camel primitives, e.g.:

[source,java]
----
@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;
----

=== Configuration properties

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.:

[source,java]
----
@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 link:http://deltaspike.apache.org/documentation/configuration.html[DeltaSpike
configuration mechanism] you can declare the
following `PropertiesComponent` bean:

[source,java]
----
@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.

=== Auto-configured type converters

CDI beans annotated with the `@Converter` annotation are automatically
registered into the deployed Camel contexts, e.g.:

[source,java]
----
@Converter
public class MyTypeConverter {

    @Converter
    public Output convert(Input input) {
        //...
    }
}
----

Note that CDI injection is supported within the type converters.

=== Camel bean integration

==== Camel annotations

As part of the Camel link:http://camel.apache.org/bean-integration.html[bean
integration], Camel comes with a set
of link:http://camel.apache.org/bean-integration.html#BeanIntegration-Annotations[annotations] that
are seamlessly supported by Camel CDI. So you can use any of these
annotations in your CDI beans, e.g.:

[width="100%",cols="1,2a,2a",options="header",]
|===
|  |Camel annotation |CDI equivalent
|Configuration property a|
[source,java]
----
@PropertyInject("key")
String value;
----

 a|
If using
http://deltaspike.apache.org/documentation/configuration.html[DeltaSpike
configuration mechanism]:

[source,java]
----
@Inject
@ConfigProperty(name = "key")
String value;
----

See configuration properties for more details.

|Producer template injection (default Camel context) a|
[source,java]
----
@Produce(uri = "mock:outbound")
ProducerTemplate producer;

// or using fluent template
@Produce(uri = "mock:outbound")
FluentProducerTemplate producer;
----

 a|
[source,java]
----
@Inject
@Uri("direct:outbound")
ProducerTemplate producer;

// or using fluent template
@Produce(uri = "direct:outbound")
FluentProducerTemplate producer;
----

|Endpoint injection (default Camel context) a|
[source,java]
----
@EndpointInject(uri = "direct:inbound")
Endpoint endpoint;
----

 a|
[source,java]
----
@Inject
@Uri("direct:inbound")
Endpoint endpoint;
----

|Endpoint injection (Camel context by name) a|
[source,java]
----
@EndpointInject(uri = "direct:inbound",
                context = "foo")
Endpoint contextEndpoint;
----

 a|
[source,java]
----
@Inject
@ContextName("foo")
@Uri("direct:inbound")
Endpoint contextEndpoint;
----

|Bean injection (by type) a|
[source,java]
----
@BeanInject
MyBean bean;
----

 a|
[source,java]
----
@Inject
MyBean bean;
----

|Bean injection (by name) a|
[source,java]
----
@BeanInject("foo")
MyBean bean;
----

 a|
[source,java]
----
@Inject
@Named("foo")
MyBean bean;
----

|POJO consuming a|
[source,java]
----
@Consume(uri = "seda:inbound")
void consume(@Body String body) {
    //...
}
----

 | 
|===

==== Bean component

You can refer to CDI beans, either by type or name, From the Camel DSL,
e.g. with the Java Camel DSL:

[source,java]
----
class MyBean {
    //...
}

from("direct:inbound").bean(MyBean.class);
----

Or to lookup a CDI bean by name from the Java DSL:

[source,java]
----
@Named("foo")
class MyNamedBean {
    //...
}

from("direct:inbound").bean("foo");
----

==== Referring beans from Endpoint URIs

When configuring endpoints using the URI syntax you can refer to beans
in the Registry using the `pass:[#]` notation. If the URI
parameter value starts with a `pass:[#]` sign then Camel CDI will lookup for a
bean of the given type by name, e.g.:

[source,java]
----
from("jms:queue:{{destination}}?transacted=true&transactionManager=#jtaTransactionManager").to("...");
----

Having the following CDI bean qualified
with `@Named("jtaTransactionManager")`:

[source,java]
----
@Produces
@Named("jtaTransactionManager")
PlatformTransactionManager createTransactionManager(TransactionManager transactionManager, UserTransaction userTransaction) {
    JtaTransactionManager jtaTransactionManager = new JtaTransactionManager();
    jtaTransactionManager.setUserTransaction(userTransaction);
    jtaTransactionManager.setTransactionManager(transactionManager);
    jtaTransactionManager.afterPropertiesSet();
    return jtaTransactionManager;
}
----

=== Camel events to CDI events

*Available as of Camel 2.17*

Camel provides a set
of link:http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/management/event/package-summary.html[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 link:http://docs.jboss.org/cdi/spec/1.2/cdi-spec.html#observer_methods[observer
methods], e.g.:

[source,java]
----
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.:

[source,java]
----
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 link:http://docs.jboss.org/cdi/spec/1.2/cdi-spec.html#observer_resolution[observer
resolution], e.g.:

[source,java]
----
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 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.:

[source,java]
----
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.

=== CDI events endpoint

*Available as of Camel 2.17*

The CDI event endpoint bridges
the link:http://docs.jboss.org/cdi/spec/1.2/cdi-spec.html#events[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:

[source,java]
----
@Inject
CdiEventEndpoint<String> cdiEventEndpoint;

from(cdiEventEndpoint).log("CDI event received: ${body}");
----

This is equivalent to writing:

[source,java]
----
@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:

[source,java]
----
@Inject
CdiEventEndpoint<String> cdiEventEndpoint;

from("direct:event").to(cdiEventEndpoint).log("CDI event sent: ${body}");
----

This is equivalent to writing:

[source,java]
----
@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:

[source,java]
----
@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.:

[source,java]
----
@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.:

[source,java]
----
@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 link:http://docs.jboss.org/cdi/spec/1.2/cdi-spec.html#observer_methods[observer
method] for each unique combination of _event type_ and _event
qualifiers_ and solely relies on the container
typesafe link:http://docs.jboss.org/cdi/spec/1.2/cdi-spec.html#observer_resolution[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 link:http://camel.apache.org/component.html[Camel component] model is
quite high, it is not possible to create an instance of the CDI event
Camel endpoint via link:http://camel.apache.org/uris.html[URIs]. Indeed, the
URI format for the CDI event component is:

[source,text]
----
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.:

[source,text]
----
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.

=== Camel XML configuration import

*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.:

[source,java]
----
@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:

[source,xml]
----
<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.:

[source,java]
----
@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:

[source,java]
----
@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.:

[source,xml]
----
<camelContext id="foo">
    <route>
        <from uri="..."/>
        <process ref="baz"/>
    </route>
<camelContext/>
----


=== Transaction support

*Available as of Camel 2.19*

Camel CDI provides support for Camel transactional client using JTA.

That support is optional hence you need to have JTA in your application classpath, e.g., by explicitly add JTA as a dependency when using Maven:

[source,xml]
----
<dependency>
    <groupId>javax.transaction</groupId>
    <artifactId>javax.transaction-api</artifactId>
    <scope>runtime</scope>
</dependency>
----

You'll have to have your application deployed in a JTA capable container or provide a standalone JTA implementation.

[CAUTION]
====
Note that, for the time being, the transaction manager is looked up as JNDI resource with the `java:/TransactionManager` key.

More flexible strategies will be added in the future to support a wider range of deployment scenarios.
====

==== Transaction policies

Camel CDI provides implementation for the typically supported Camel `TransactedPolicy` as CDI beans. It is possible to have these policies looked up by name using the transacted EIP, e.g.:

[source,java]
----
class MyRouteBean extends RouteBuilder {

    @Override
    public void configure() {
        from("activemq:queue:foo")
            .transacted("PROPAGATION_REQUIRED")
            .bean("transformer")
            .to("jpa:my.application.entity.Bar")
            .log("${body.id} inserted");
    }
}
----

This would be equivalent to:

[source,java]
----
class MyRouteBean extends RouteBuilder {

    @Inject
    @Named("PROPAGATION_REQUIRED")
    Policy required;

    @Override
    public void configure() {
        from("activemq:queue:foo")
            .policy(required)
            .bean("transformer")
            .to("jpa:my.application.entity.Bar")
            .log("${body.id} inserted");
    }
}
----

The list of supported transaction policy names is:

- `PROPAGATION_NEVER`,
- `PROPAGATION_NOT_SUPPORTED`,
- `PROPAGATION_SUPPORTS`,
- `PROPAGATION_REQUIRED`,
- `PROPAGATION_REQUIRES_NEW`,
- `PROPAGATION_NESTED`,
- `PROPAGATION_MANDATORY`.

==== Transactional error handler

Camel CDI provides a transactional error handler that extends the redelivery error handler, forces a rollback whenever an exception occurs and creates a new transaction for each redelivery.

Camel CDI provides the `CdiRouteBuilder` class that exposes the `transactionErrorHandler` helper method to enable quick access to the configuration, e.g.:

[source,java]
----
class MyRouteBean extends CdiRouteBuilder {

    @Override
    public void configure() {
        errorHandler(transactionErrorHandler()
            .setTransactionPolicy("PROPAGATION_SUPPORTS")
            .maximumRedeliveries(5)
            .maximumRedeliveryDelay(5000)
            .collisionAvoidancePercent(10)
            .backOffMultiplier(1.5));
    }
}
----


=== Auto-configured OSGi integration

*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.:

[source,text]
----
karaf@root()> camel:context-list
 Context        Status              Total #       Failed #     Inflight #   Uptime
 -------        ------              -------       --------     ----------   ------
 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.


=== Lazy Injection / Programmatic Lookup

While the CDI programmatic model favors a http://docs.jboss.org/cdi/spec/1.2/cdi-spec.html#typesafe_resolution[typesafe resolution]
mechanism that occurs at application initialization time, it is possible to perform
dynamic / lazy injection later during the application execution using the
http://docs.jboss.org/cdi/spec/1.2/cdi-spec.html#programmatic_lookup[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:

[source,java]
----
@Any
@Inject
Instance<ProducerTemplate> producers;

ProducerTemplate inbound = producers
    .select(Uri.Literal.of("direct:inbound"))
    .get();
----

Or for `Endpoint` beans, e.g.:

[source,java]
----
@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.:

[source,java]
----
@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.:

[source,java]
----
@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.:

[source,java]
----
@Any
@Inject
Instance<CamelContext> contexts;

for (CamelContext context : contexts)
    context.setUseBreadcrumb(true);
----


=== Maven Archetype

Among the available link:camel-maven-archetypes.html[Camel Maven
archetypes], you can use the provided `camel-archetype-cdi` to generate
a Camel CDI Maven project, e.g.:

[source,text]
----
mvn archetype:generate -DarchetypeGroupId=org.apache.camel.archetypes -DarchetypeArtifactId=camel-archetype-cdi
----

=== Supported containers

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:

[width="100%",cols="2,1m,2",options="header",]
|============================================
|Container |Version |Runtime
|Weld SE |1.1.28.Final |CDI 1.0 / Java SE 7
|OpenWebBeans |1.2.7 |CDI 1.0 / Java SE 7
|Weld SE |2.4.2.Final |CDI 1.2 / Java SE 7
|OpenWebBeans |1.7.2 |CDI 1.2 / Java SE 7
|WildFly |8.2.1.Final |CDI 1.2 / Java EE 7
|WildFly |9.0.1.Final |CDI 1.2 / Java EE 7
|WildFly |10.1.0.Final |CDI 1.2 / Java EE 7
|============================================


=== Examples

The following examples are available in the `examples` directory of the
Camel project:

[width="100%",cols="1m,3",options="header",]
|===
|Example |Description

|camel-example-cdi
|Illustrates how to work with Camel using CDI to configure components,
endpoints and beans

|camel-example-cdi-kubernetes
|Illustrates the integration between Camel, CDI and Kubernetes

|camel-example-cdi-metrics
|Illustrates the integration between Camel, Dropwizard Metrics and CDI

|camel-example-cdi-properties
|Illustrates the integration between Camel, DeltaSpike and CDI for
configuration properties

|camel-example-cdi-osgi
|A CDI application using the SJMS component that can be executed
inside an OSGi container using PAX CDI

|camel-example-cdi-rest-servlet
|Illustrates the Camel REST DSL being used in a Web application that
uses CDI as dependency injection framework

|camel-example-cdi-test
|Demonstrates the testing features that are provided as part of
the integration between Camel and CDI

|camel-example-cdi-xml
|Illustrates the use of Camel XML configuration
files into a Camel CDI application

|camel-example-swagger-cdi
|An example using REST DSL and Swagger Java with CDI

|camel-example-widget-gadget-cdi
|The Widget and Gadget use-case from the EIP book implemented
in Java with CDI dependency Injection

|===

=== See Also

* Camel CDI testing
* http://www.cdi-spec.org[CDI specification Web site]
* http://www.cdi-spec.org/ecosystem/[CDI ecosystem]
* http://weld.cdi-spec.org[Weld home page]
* http://openwebbeans.apache.org[OpenWebBeans home page]
* https://github.com/astefanutti/further-cdi[Going further with CDI and Camel]
(See Camel CDI section)
