Chapter 135. 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.
135.1. 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:
135.1.1. Path Parameters (1 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| cacheName | Required The name of the cache | String |
135.1.2. 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 |
135.2. Spring Boot Auto-Configuration
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 |
135.3. 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 |
|---|---|---|
|
|
| as already described. |
|
|
| 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 |
|---|---|---|
|
|
| value of TTL. |
|
|
| 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");135.3.1. 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>135.3.2. 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>135.3.3. 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>135.3.4. 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>135.3.5. 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);135.4. 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 |
|---|---|---|
|
|
| time of the event in millis |
|
|
| the map consumer sets here "cachelistener" |
|
|
| type of event - here added, updated, envicted and removed. |
|
|
| the oid of the object |
|
|
| the name of the cache - e.g. "foo" |
|
|
| 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!");