Hazelcast Map Component

Available as of Camel version 2.7

The Hazelcast Map component is one of Camel Hazelcast Components which allows you to access Hazelcast distributed map.

Options

The Hazelcast Map component supports 3 options, which are listed below.

Name Description Default Type

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

resolveProperty Placeholders (advanced)

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

boolean

The Hazelcast Map endpoint is configured using URI syntax:

hazelcast-map:cacheName

with the following path and query parameters:

Path Parameters (1 parameters):

Name Description Default Type

cacheName

Required The name of the cache

String

Query Parameters (16 parameters):

Name Description Default Type

defaultOperation (common)

To specify a default operation to use, if no operation header has been provided.

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

pollingTimeout (consumer)

Define the polling timeout of the Queue consumer in Poll mode

10000

long

poolSize (consumer)

Define the Pool size for Queue Consumer Executor

1

int

queueConsumerMode (consumer)

Define the Queue Consumer mode: Listen or Poll

Listen

HazelcastQueueConsumer Mode

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.

ExchangePattern

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

concurrentConsumers (seda)

To use concurrent consumers polling from the SEDA queue.

1

int

onErrorDelay (seda)

Milliseconds before consumer continues polling after an error has occurred.

1000

int

pollTimeout (seda)

The timeout used when consuming from the SEDA queue. When a timeout occurs, the consumer can check whether it is allowed to continue running. Setting a lower value allows the consumer to react more quickly upon shutdown.

1000

int

transacted (seda)

If set to true then the consumer runs in transaction mode, where the messages in the seda queue will only be removed if the transaction commits, which happens when the processing is complete.

false

boolean

transferExchange (seda)

If set to true the whole Exchange will be transfered. If header or body contains not serializable objects, they will be skipped.

false

boolean

Spring Boot Auto-Configuration

When using Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-hazelcast-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 6 options, which are listed below.

Name Description Default Type

camel.component.hazelcast-map.customizer.hazelcast-instance.enabled

Enable or disable the cache-manager customizer.

true

Boolean

camel.component.hazelcast-map.customizer.hazelcast-instance.override

Configure if the cache manager eventually set on the component should be overridden by the customizer.

false

Boolean

camel.component.hazelcast-map.enabled

Enable hazelcast-map component

true

Boolean

camel.component.hazelcast-map.hazelcast-instance

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. The option is a com.hazelcast.core.HazelcastInstance type.

String

camel.component.hazelcast-map.hazelcast-mode

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

camel.component.hazelcast-map.resolve-property-placeholders

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

Boolean

Map cache producer - to("hazelcast-map:foo")

If you want to store a value in a map you can use the map cache producer.

The map cache producer provides follow operations specified by CamelHazelcastOperationType header:

  • put

  • putIfAbsent

  • get

  • getAll

  • keySet

  • containsKey

  • containsValue

  • delete

  • update

  • query

  • clear

  • evict

  • evictAll

All operations are provide the inside the "hazelcast.operation.type" header variable. In Java DSL you can use the constants from org.apache.camel.component.hazelcast.HazelcastOperation.

Header Variables for the request message:

Name Type Description

CamelHazelcastOperationType

String

as already described.

CamelHazelcastObjectId

String

the object id to store / find your object inside the cache (not needed for the query operation)

put and putIfAbsent operations provide an eviction mechanism:

Name Type Description

CamelHazelcastObjectTtlValue

Integer

value of TTL.

CamelHazelcastObjectTtlUnit

java.util.concurrent.TimeUnit

value of time unit ( DAYS / HOURS / MINUTES / …​.

You can call the samples with:

template.sendBodyAndHeader("direct:[put|get|update|delete|query|evict]", "my-foo", HazelcastConstants.OBJECT_ID, "4711");

Sample for put:

Java DSL:

from("direct:put")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.PUT))
.toF("hazelcast-%sfoo", HazelcastConstants.MAP_PREFIX);

Spring DSL:

<route>
    <from uri="direct:put" />
        <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" -->
    <setHeader headerName="hazelcast.operation.type">
        <constant>put</constant>
    </setHeader>
    <to uri="hazelcast-map:foo" />
</route>

Sample for put with eviction:

Java DSL:

from("direct:put")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.PUT))
.setHeader(HazelcastConstants.TTL_VALUE, constant(Long.valueOf(1)))
.setHeader(HazelcastConstants.TTL_UNIT, constant(TimeUnit.MINUTES))
.toF("hazelcast-%sfoo", HazelcastConstants.MAP_PREFIX);

Spring DSL:

<route>
    <from uri="direct:put" />
        <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" -->
    <setHeader headerName="hazelcast.operation.type">
        <constant>put</constant>
    </setHeader>
    <setHeader headerName="HazelcastConstants.TTL_VALUE">
        <simple resultType="java.lang.Long">1</simple>
    </setHeader>
    <setHeader headerName="HazelcastConstants.TTL_UNIT">
        <simple resultType="java.util.concurrent.TimeUnit">TimeUnit.MINUTES</simple>
    </setHeader>
    <to uri="hazelcast-map:foo" />
</route>

Sample for get:

Java DSL:

from("direct:get")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.GET))
.toF("hazelcast-%sfoo", HazelcastConstants.MAP_PREFIX)
.to("seda:out");

Spring DSL:

<route>
    <from uri="direct:get" />
        <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" -->
    <setHeader headerName="hazelcast.operation.type">
        <constant>get</constant>
    </setHeader>
    <to uri="hazelcast-map:foo" />
    <to uri="seda:out" />
</route>

Sample for update:

Java DSL:

from("direct:update")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.UPDATE))
.toF("hazelcast-%sfoo", HazelcastConstants.MAP_PREFIX);

Spring DSL:

<route>
    <from uri="direct:update" />
        <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" -->
    <setHeader headerName="hazelcast.operation.type">
        <constant>update</constant>
    </setHeader>
    <to uri="hazelcast-map:foo" />
</route>

Sample for delete:

Java DSL:

from("direct:delete")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.DELETE))
.toF("hazelcast-%sfoo", HazelcastConstants.MAP_PREFIX);

Spring DSL:

<route>
    <from uri="direct:delete" />
        <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" -->
    <setHeader headerName="hazelcast.operation.type">
        <constant>delete</constant>
    </setHeader>
    <to uri="hazelcast-map:foo" />
</route>

Sample for query

Java DSL:

from("direct:query")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.QUERY))
.toF("hazelcast-%sfoo", HazelcastConstants.MAP_PREFIX)
.to("seda:out");

Spring DSL:

<route>
    <from uri="direct:query" />
        <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" -->
    <setHeader headerName="hazelcast.operation.type">
        <constant>query</constant>
    </setHeader>
    <to uri="hazelcast-map:foo" />
    <to uri="seda:out" />
</route>

For the query operation Hazelcast offers a SQL like syntax to query your distributed map.

String q1 = "bar > 1000";
template.sendBodyAndHeader("direct:query", null, HazelcastConstants.QUERY, q1);

Map cache consumer - from("hazelcast-map:foo")

Hazelcast provides event listeners on their data grid. If you want to be notified if a cache will be manipulated, you can use the map consumer. There’re 4 events: put, update, delete and envict. The event type will be stored in the "hazelcast.listener.action" header variable. The map consumer provides some additional information inside these variables:

Header Variables inside the response message:

Name Type Description

CamelHazelcastListenerTime

Long

time of the event in millis

CamelHazelcastListenerType

String

the map consumer sets here "cachelistener"

CamelHazelcastListenerAction

String

type of event - here added, updated, envicted and removed.

CamelHazelcastObjectId

String

the oid of the object

CamelHazelcastCacheName

String

the name of the cache - e.g. "foo"

CamelHazelcastCacheType

String

the type of the cache - here map

The object value will be stored within put and update actions inside the message body.

Here’s a sample:

fromF("hazelcast-%sfoo", HazelcastConstants.MAP_PREFIX)
.log("object...")
.choice()
    .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ADDED))
         .log("...added")
         .to("mock:added")
    .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ENVICTED))
         .log("...envicted")
         .to("mock:envicted")
    .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.UPDATED))
         .log("...updated")
         .to("mock:updated")
    .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.REMOVED))
         .log("...removed")
         .to("mock:removed")
    .otherwise()
         .log("fail!");