Hazelcast Map
Since Camel 2.7
Both producer and consumer are supported
The Hazelcast Map component is one of Camel Hazelcast Components which allows you to access Hazelcast distributed map.
Configuring Options
Camel components are configured on two separate levels:
-
component level
-
endpoint level
Configuring Component Options
The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.
Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.
Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.
Configuring Endpoint Options
Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.
Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL as a type safe way of configuring endpoints.
A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.
The following two sections lists all the options, firstly for the component followed by the endpoint.
Component Options
The Hazelcast Map component supports 5 options, which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
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 |
|
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 |
|
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 |
|
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 |
||
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 |
Endpoint Options
The Hazelcast Map endpoint is configured using URI syntax:
hazelcast-map:cacheName
with the following path and query parameters:
Query Parameters (7 parameters)
| Name | Description | Default | Type |
|---|---|---|---|
To specify a default operation to use, if no operation header has been provided. Enum values:
|
HazelcastOperation |
||
The hazelcast instance reference which can be used for hazelcast endpoint. |
HazelcastInstance |
||
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 |
||
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 |
|
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 |
||
Sets the exchange pattern when the consumer creates an exchange. Enum values:
|
ExchangePattern |
||
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 |
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");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" />
<setHeader name="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" />
<setHeader name="hazelcast.operation.type">
<constant>put</constant>
</setHeader>
<setHeader name="HazelcastConstants.TTL_VALUE">
<simple resultType="java.lang.Long">1</simple>
</setHeader>
<setHeader name="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" />
<setHeader name="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" />
<setHeader name="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" />
<setHeader name="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" />
<setHeader name="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 |
|---|---|---|
|
|
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!");Spring Boot Auto-Configuration
When using hazelcast-map with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-hazelcast-starter</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>The component supports 63 options, which are listed below.