[[hazelcast-topic-component]]
= Hazelcast Topic Component
:docTitle: Hazelcast Topic
:artifactId: camel-hazelcast
:description: Send and receive messages to/from Hazelcast distributed topic.
:since: 2.15
:supportLevel: Stable
:component-header: Both producer and consumer are supported
include::{cq-version}@camel-quarkus:ROOT:partial$reference/components/hazelcast-topic.adoc[opts=optional]
//Manually maintained attributes
:group: Hazelcast

*Since Camel {since}*

*{component-header}*

The http://www.hazelcast.com/[Hazelcast] Topic component is one of Camel Hazelcast Components which allows you to access Hazelcast distributed topic.


== Options

// component options: START
The Hazelcast Topic component supports 5 options, which are listed below.



[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *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 or ERROR level and ignored. | false | boolean
| *lazyStartProducer* (producer) | Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel's routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. | false | boolean
| *autowiredEnabled* (advanced) | Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. | true | boolean
| *hazelcastInstance* (advanced) | The hazelcast instance reference which can be used for hazelcast endpoint. If you don't specify the instance reference, camel use the default hazelcast instance from the camel-hazelcast instance. |  | HazelcastInstance
| *hazelcastMode* (advanced) | The hazelcast mode reference which kind of instance should be used. If you don't specify the mode, then the node mode will be the default. | node | String
|===
// component options: END
// endpoint options: START
The Hazelcast Topic endpoint is configured using URI syntax:

----
hazelcast-topic:cacheName
----

with the following path and query parameters:

=== Path Parameters (1 parameters):


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|===
| Name | Description | Default | Type
| *cacheName* | *Required* The name of the cache |  | String
|===


=== Query Parameters (9 parameters):


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|===
| Name | Description | Default | Type
| *defaultOperation* (common) | To specify a default operation to use, if no operation header has been provided. There are 36 enums and the value can be one of: put, delete, get, update, query, getAll, clear, putIfAbsent, allAll, removeAll, retainAll, evict, evictAll, valueCount, containsKey, containsValue, keySet, removevalue, increment, decrement, setvalue, destroy, compareAndSet, getAndAdd, add, offer, peek, poll, remainingCapacity, drainTo, removeIf, take, publish, readOnceHeal, readOnceTail, capacity |  | HazelcastOperation
| *hazelcastInstance* (common) | The hazelcast instance reference which can be used for hazelcast endpoint. |  | HazelcastInstance
| *hazelcastInstanceName* (common) | The hazelcast instance reference name which can be used for hazelcast endpoint. If you don't specify the instance reference, camel use the default hazelcast instance from the camel-hazelcast instance. |  | String
| *reliable* (common) | Define if the endpoint will use a reliable Topic struct or not. | false | boolean
| *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 or ERROR level and ignored. | false | boolean
| *exceptionHandler* (consumer) | To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored. |  | ExceptionHandler
| *exchangePattern* (consumer) | Sets the exchange pattern when the consumer creates an exchange. There are 3 enums and the value can be one of: InOnly, InOut, InOptionalOut |  | ExchangePattern
| *lazyStartProducer* (producer) | Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel's routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. | false | boolean
| *synchronous* (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean
|===
// endpoint options: END




== Topic producer – to(“hazelcast-topic:foo”)

The topic producer provides only one operation (publish).

=== Sample for *publish*:

[source,java]
----------------------------------------------------------------------------------------
from("direct:add")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.PUBLISH))
.toF("hazelcast-%sbar", HazelcastConstants.PUBLISH_OPERATION);
----------------------------------------------------------------------------------------

== Topic consumer – from(“hazelcast-topic:foo”)

The topic consumer provides only one operation (received). This
component is supposed to support multiple consumption as it's expected
when it comes to topics so you are free to have as much consumers as you
need on the same hazelcast topic.

[source,java]
--------------------------------------------------------------------------------------------
fromF("hazelcast-%sfoo", HazelcastConstants.TOPIC_PREFIX)
  .choice()
    .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.RECEIVED))
      .log("...message received")
    .otherwise()
      .log("...this should never have happened")
--------------------------------------------------------------------------------------------

include::camel-spring-boot::page$hazelcast-starter.adoc[]
