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The hazelcast: component allows you to work with the Hazelcast distributed data grid / cache. Hazelcast is a in memory data grid, entirely written in Java (single jar). It offers a great palette of different data stores like map, multi map (same key, n values), queue, list and atomic number. The main reason to use Hazelcast is its simple cluster support. If you have enabled multicast on your network you can run a cluster with hundred nodes with no extra configuration. Hazelcast can simply configured to add additional features like n copies between nodes (default is 1), cache persistence, network configuration (if needed), near cache, enviction and so on. For more information consult the Hazelcast documentation on http://www.hazelcast.com/documentation.jsp.
Maven users will need to add the following dependency to their pom.xml
for this component:
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<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-hazelcast</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
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URI format
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hazelcast:[map | multimap | queue | seda | set | atomicvalue | instance]:cachename[?options]
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Warning |
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You have to use the second prefix to define which type of data store you want to use. |
Usage of Map Cache
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 5 operations (put, get, update, delete, query). For the first 4 you have to provide the operation inside the "hazelcast.operation.type" header variable. In Java DSL you can use the constants from org.apache.camel.component.hazelcast.HazelcastConstants
.
Header Variables for the request message:
Name | Type | Description |
---|---|---|
| | valid values are: put, delete, get, update, query |
| | the object id to store / find your object inside the cache (not needed for the query operation) |
You can call the samples with:
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template.sendBodyAndHeader("direct:[put|get|update|delete|query]", "my-foo", HazelcastConstants.OBJECT_ID, "4711");
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Sample for put:
Java DSL:
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from("direct:put")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.PUT_OPERATION))
.to(String.format("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX));
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Spring DSL:
Code Block |
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<route>
<from uri="direct:put" />
<setHeader headerName="hazelcast.operation.type">
<constant>put</constant>
</setHeader>
<to uri="hazelcast:map:foo" />
</route>
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Sample for get:
Java DSL:
Code Block |
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from("direct:get")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.GET_OPERATION))
.to(String.format("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX))
.to("seda:out");
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Spring DSL:
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<route>
<from uri="direct:get" />
<setHeader headerName="hazelcast.operation.type">
<constant>get</constant>
</setHeader>
<to uri="hazelcast:map:foo" />
<to uri="seda:out" />
</route>
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Sample for update:
Java DSL:
Code Block |
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from("direct:update")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.UPDATE_OPERATION))
.to(String.format("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX));
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Spring DSL:
Code Block |
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<route>
<from uri="direct:update" />
<setHeader headerName="hazelcast.operation.type">
<constant>update</constant>
</setHeader>
<to uri="hazelcast:map:foo" />
</route>
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Sample for delete:
Java DSL:
Code Block |
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from("direct:delete")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.DELETE_OPERATION))
.to(String.format("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX));
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Spring DSL:
Code Block |
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<route>
<from uri="direct:delete" />
<setHeader headerName="hazelcast.operation.type">
<constant>delete</constant>
</setHeader>
<to uri="hazelcast:map:foo" />
</route>
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Sample for query
Java DSL:
Code Block |
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from("direct:query")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.QUERY_OPERATION))
.to(String.format("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX))
.to("seda:out");
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Spring DSL:
Code Block |
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<route>
<from uri="direct:query" />
<setHeader headerName="hazelcast.operation.type">
<constant>query</constant>
</setHeader>
<to uri="hazelcast:map:foo" />
<to uri="seda:out" />
</route>
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For the query operation Hazelcast offers a SQL like syntax to query your distributed map.
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String q1 = "bar > 1000";
template.sendBodyAndHeader("direct:query", null, HazelcastConstants.QUERY, q1);
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map cache consumer - from("hazelcast:map:foo")
Hazelcast as simple as the Cache component 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:
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from(String.format("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!");
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Usage of Multi Map Cache
multimap cache producer - to("hazelcast:multimap:foo")
A multimap is a cache where you can store n values to one key. The multimap producer provides 4 operations (put, get, removevalue, delete).
Header Variables for the request message:
Name | Type | Description |
---|---|---|
| | valid values are: put, get, removevalue, delete |
| | the object id to store / find your object inside the cache |
Sample for put:
Java DSL:
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from("direct:put")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.PUT_OPERATION))
.to(String.format("hazelcast:%sbar", HazelcastConstants.MULTIMAP_PREFIX));
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Spring DSL:
Code Block |
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<route>
<from uri="direct:put" />
<log message="put.."/>
<setHeader headerName="hazelcast.operation.type">
<constant>put</constant>
</setHeader>
<to uri="hazelcast:multimap:foo" />
</route>
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Sample for removevalue:
Java DSL:
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from("direct:removevalue")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.REMOVEVALUE_OPERATION))
.to(String.format("hazelcast:%sbar", HazelcastConstants.MULTIMAP_PREFIX));
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Spring DSL:
Code Block |
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<route>
<from uri="direct:removevalue" />
<log message="removevalue..."/>
<setHeader headerName="hazelcast.operation.type">
<constant>removevalue</constant>
</setHeader>
<to uri="hazelcast:multimap:foo" />
</route>
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To remove a value you have to provide the value you want to remove inside the message body. If you have a multimap object {key: "4711" values: { "my-foo", "my-bar"
}} you have to put "my-foo" inside the message body to remove the "my-foo" value.
Sample for get:
Java DSL:
Code Block |
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from("direct:get")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.GET_OPERATION))
.to(String.format("hazelcast:%sbar", HazelcastConstants.MULTIMAP_PREFIX))
.to("seda:out");
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Spring DSL:
Code Block |
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<route>
<from uri="direct:get" />
<log message="get.."/>
<setHeader headerName="hazelcast.operation.type">
<constant>get</constant>
</setHeader>
<to uri="hazelcast:multimap:foo" />
<to uri="seda:out" />
</route>
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Sample for delete:
Java DSL:
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from("direct:delete")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.DELETE_OPERATION))
.to(String.format("hazelcast:%sbar", HazelcastConstants.MULTIMAP_PREFIX));
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Spring DSL:
Code Block |
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<route>
<from uri="direct:delete" />
<log message="delete.."/>
<setHeader headerName="hazelcast.operation.type">
<constant>delete</constant>
</setHeader>
<to uri="hazelcast:multimap:foo" />
</route>
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you can call them in your test class with:
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template.sendBodyAndHeader("direct:[put|get|removevalue|delete]", "my-foo", HazelcastConstants.OBJECT_ID, "4711");
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multimap cache consumer - from("hazelcast:multimap:foo")
For the multimap cache this component provides the same listeners / variables as for the map cache consumer (except the update and enviction listener). The only difference is the multimap prefix inside the URI. Here is a sample:
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from(String.format("hazelcast:%sbar", HazelcastConstants.MULTIMAP_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.REMOVED))
.log("...removed")
.to("mock:removed")
.otherwise()
.log("fail!");
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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 and removed (and soon envicted) |
| | the oid of the object |
| | the name of the cache - e.g. "foo" |
| | the type of the cache - here multimap |
Enviction will be added as feature, soon (this is a Hazelcast issue).
atomic number
Warning |
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There is no consumer for this component! |
atomic number producer - to("hazelcast:atomicnumber:foo")
An atomic number is an object that simply provides a grid wide number (long). The operations for this producer are setvalue (set the number with a given value), get, increase (+1), decrease (-1) and destroy.
Header Variables for the request message:
Name | Type | Description |
---|---|---|
| | valid values are: setvalue, get, increase, decrease, destroy |
Sample for set:
Java DSL:
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from("direct:set")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.SETVALUE_OPERATION))
.to(String.format("hazelcast:%sfoo", HazelcastConstants.ATOMICNUMBER_PREFIX));
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Spring DSL:
Code Block |
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<route>
<from uri="direct:set" />
<setHeader headerName="hazelcast.operation.type">
<constant>setvalue</constant>
</setHeader>
<to uri="hazelcast:atomicvalue:foo" />
</route>
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Provide the value to set inside the message body (here the value is 10): template.sendBody("direct:set", 10);
Sample for get:
Java DSL:
Code Block |
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from("direct:get")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.GET_OPERATION))
.to(String.format("hazelcast:%sfoo", HazelcastConstants.ATOMICNUMBER_PREFIX));
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Spring DSL:
Code Block |
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<route>
<from uri="direct:get" />
<setHeader headerName="hazelcast.operation.type">
<constant>get</constant>
</setHeader>
<to uri="hazelcast:atomicvalue:foo" />
</route>
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You can get the number with long body = template.requestBody("direct:get", null, Long.class);
.
Sample for increment:
Java DSL:
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from("direct:increment")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.INCREMENT_OPERATION))
.to(String.format("hazelcast:%sfoo", HazelcastConstants.ATOMICNUMBER_PREFIX));
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Spring DSL:
Code Block |
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<route>
<from uri="direct:increment" />
<setHeader headerName="hazelcast.operation.type">
<constant>increment</constant>
</setHeader>
<to uri="hazelcast:atomicvalue:foo" />
</route>
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The actual value (after increment) will be provided inside the message body.
Sample for decrement:
Java DSL:
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from("direct:decrement")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.DECREMENT_OPERATION))
.to(String.format("hazelcast:%sfoo", HazelcastConstants.ATOMICNUMBER_PREFIX));
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Spring DSL:
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<route>
<from uri="direct:decrement" />
<setHeader headerName="hazelcast.operation.type">
<constant>decrement</constant>
</setHeader>
<to uri="hazelcast:atomicvalue:foo" />
</route>
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The actual value (after decrement) will be provided inside the message body.
Sample for destroy
Warning |
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There's a bug inside Hazelcast. So this feature may not work properly. Will be fixed in 1.9.3. |
Java DSL:
Code Block |
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from("direct:destroy")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.DESTROY_OPERATION))
.to(String.format("hazelcast:%sfoo", HazelcastConstants.ATOMICNUMBER_PREFIX));
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Spring DSL:
Code Block |
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<route>
<from uri="direct:destroy" />
<setHeader headerName="hazelcast.operation.type">
<constant>destroy</constant>
</setHeader>
<to uri="hazelcast:atomicvalue:foo" />
</route>
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cluster support
Warning |
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This endpoint provides no producer! |
instance consumer - from("hazelcast:instance:foo")
Hazelcast makes sense in one single "server node", but it's extremly powerful in a clustered environment. The instance consumer fires if a new cache instance will join or leave the cluster.
Here's a sample:
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from(String.format("hazelcast:%sfoo", HazelcastConstants.INSTANCE_PREFIX))
.log("instance...")
.choice()
.when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ADDED))
.log("...added")
.to("mock:added")
.otherwise()
.log("...removed")
.to("mock:removed");
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Each event provides the following information inside the message header:
Header Variables inside the response message:
Name | Type | Description |
---|---|---|
| | time of the event in millis |
| | the map consumer sets here "instancelistener" |
| | type of event - here added or removed |
| | host name of the instance |
| | port number of the instance |