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Cache Component

Warning
This component is deprecated. As of Camel 2.18.0 You should use Ehcache.

Available as of Camel 2.1

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Maven users will need to add the following dependency to their pom.xml for this component:

Code Block

	xml
	xml


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

URI format

Code Block
cache://cacheName[?options]

You can append query options to the URI in the following format, ?option=value&option=#beanRef&...

Options

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Name	Default Value	Description
`maxElementsInMemory`	`1000`	The number of elements that may be stored in the defined cache
`memoryStoreEvictionPolicy`	`MemoryStoreEvictionPolicy.LFU`	The number of elements that may be stored in the defined cache. Options include MemoryStoreEvictionPolicy.LFU - Least frequently used MemoryStoreEvictionPolicy.LRU - Least recently used MemoryStoreEvictionPolicy.FIFO - first in first out, the oldest element by creation time
`overflowToDisk`	`true`	Specifies whether cache may overflow to disk
`eternal`	`false`	Sets whether elements are eternal. If eternal, timeouts are ignored and the element never expires.
`timeToLiveSeconds`	`300`	The maximum time between creation time and when an element expires. Is used only if the element is not eternal
`timeToIdleSeconds`	`300`	The maximum amount of time between accesses before an element expires
`diskPersistent`	`false`	Whether the disk store persists between restarts of the Virtual Machine.
`diskExpiryThreadIntervalSeconds`	`120`	The number of seconds between runs of the disk expiry thread.
`cacheManagerFactory`	`null`	Camel 2.8: If you want to use a custom factory which instantiates and creates the EHCache `net.sf.ehcache.CacheManager`. Type: abstract

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org.apache.camel.component.cache.CacheManagerFactory

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`eventListenerRegistry`	`null`	Camel 2.8:

...

Sets a

...

list

...

of

...

EHCache

...

net.sf.ehcache.event.CacheEventListener

...

for

...

all

...

new

...

caches

...

-

...

no

...

need

...

to

...

define

...

it

...

per

...

cache

...

in

...

EHCache

...

xml

...

config

...

anymore.

...

Type:

...

org.apache.camel.component.cache.CacheEventListenerRegistry

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`cacheLoaderRegistry`	`null`	Camel 2.8:

...

Sets

...

a

...

list

...

of

...

org.apache.camel.component.cache.CacheLoaderWrapper

...

that

...

extends

...

EHCache

...

net.sf.ehcache.loader.CacheLoader

...

for

...

all

...

new

...

caches

...

-

...

no

...

need

...

to

...

define

...

it

...

per

...

cache

...

in

...

EHCache

...

xml

...

config

...

anymore.

...

Type:

...

org.apache.camel.component.cache.CacheLoaderRegistry

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`key`	`null`	Camel 2.10:

...

To

...

configure

...

using

...

a

...

cache

...

key

...

by

...

default.

...

If

...

a

...

key

...

is

...

provided

...

in

...

the

...

message

...

header,

...

then

...

the

...

key

...

from

...

the

...

header

...

takes

...

precedence.

...


`operation`	`null`	Camel 2.10:

...

To

...

configure

...

using

...

an

...

cache

...

operation

...

by

...

default.

...

If

...

an

...

operation

...

in

...

the

...

message

...

header,

...

then

...

the

...

operation

...

from

...

the

...

header

...

takes

...

precedence.

...


objectCache	false	Camel 2.15: Whether to turn on allowing to store non serializable objects in the cache. If this option is enabled then overflow to disk cannot be enabled as well.

Cache Component options

Name	Default Value	Description
`configuration`		To use a custom `org.apache.camel.component.cache.CacheConfiguration` configuration.
`cacheManagerFactory`		To use a custom `org.apache.camel.component.cache.CacheManagerFactory`.
`configurationFile`		Camel 2.13/2.12.3: To configure the location of the `ehcache.xml` file to use, such as `classpath:com/foo/mycache.xml` to load from classpath. If no configuration is given, then the default settings from EHCache is used.

Sending/Receiving Messages to/from the cache

Message Headers up to Camel 2.7

Div

class	confluenceTableSmall

Header

Description

CACHE_OPERATION

The operation to be performed on the cache. Valid options are

GET
CHECK
ADD
UPDATE
DELETE
DELETEALL
GET and CHECK requires Camel 2.3 onwards.

CACHE_KEY

The cache key used to store the Message in the cache. The cache key is optional if the CACHE_OPERATION is DELETEALL

Sending/Receiving Messages to/from the cache

Message Headers up to Camel 2.7

Wiki Markup

{div:class=confluenceTableSmall} || Header || Description || | {{CACHE_OPERATION}} | The operation to be performed on the cache. Valid options are - GET - CHECK - ADD - UPDATE - DELETE - DELETEALL\\ {{GET}} and {{CHECK}} requires *Camel 2.3* onwards. | | {{CACHE_KEY}} | The cache key used to store the Message in the cache. The cache key is optional if the CACHE_OPERATION is DELETEALL | {div}

Message Headers Camel 2.8+

Info

title	Header changes in Camel 2.8

The header names and supported values have changed to be prefixed with 'CamelCache' and use mixed case. This makes them easier to identify and keep separate from other headers. The CacheConstants variable names remain unchanged, just their values have been changed. Also, these headers are now removed from the exchange after the cache operation is performed.

Div

class	confluenceTableSmall

Header

Description

CamelCacheOperation

The operation to be performed on the cache. The valid options are

CamelCacheGet
CamelCacheCheck
CamelCacheAdd
CamelCacheUpdate
CamelCacheDelete
CamelCacheDeleteAll

CamelCacheKey

The cache key used to store the Message in the cache. The cache key is optional if the CamelCacheOperation is CamelCacheDeleteAll

Wiki Markup

{div:class=confluenceTableSmall} || Header || Description || | {{CamelCacheOperation}} | The operation to be performed on the cache. The valid options are - CamelCacheGet - CamelCacheCheck - CamelCacheAdd - CamelCacheUpdate - CamelCacheDelete - CamelCacheDeleteAll | | {{CamelCacheKey}} | The cache key used to store the Message in the cache. The cache key is optional if the CamelCacheOperation is CamelCacheDeleteAll | {div}

The CamelCacheAdd and CamelCacheUpdate operations support additional headers:

Div

class	confluenceTableSmall

Header	Type	Description
`CamelCacheTimeToLive`	`Integer`	Camel

Wiki Markup

{div:class=confluenceTableSmall} || Header || Type || Description || | {{CamelCacheTimeToLive}} | {{Integer}} | *Camel

2.11:

*

Time

to

live

in

seconds.

| | {{CamelCacheTimeToIdle}} | {{Integer}} | *Camel


`CamelCacheTimeToIdle`	`Integer`	Camel 2.11:

*

Time

to

idle

in

seconds.

| | {{CamelCacheEternal}} | {{Boolean}} | *Camel


`CamelCacheEternal`	`Boolean`	Camel 2.11:

*

Whether

the

content

is

eternal.

| {div}

Cache Producer

Sending data to the cache involves the ability to direct payloads in exchanges to be stored in a pre-existing or created-on-demand cache. The mechanics of doing this involve

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Example 1: Configuring the cache

Code Block


from("cache://MyApplicationCache" +
          "?maxElementsInMemory=1000" +
          "&memoryStoreEvictionPolicy=" +
              "MemoryStoreEvictionPolicy.LFU" +
          "&overflowToDisk=true" +
          "&eternal=true" +
          "&timeToLiveSeconds=300" +
          "&timeToIdleSeconds=true" +
          "&diskPersistent=true" +
          "&diskExpiryThreadIntervalSeconds=300")

Example 2: Adding keys to the cache

Code Block


RouteBuilder builder = new RouteBuilder() {
    public void configure() {
     from("direct:start")
     .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_ADD))
     .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson"))
     .to("cache://TestCache1")
   }
};

Example 2: Updating existing keys in a cache

Code Block


RouteBuilder builder = new RouteBuilder() {
    public void configure() {
     from("direct:start")
     .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_UPDATE))
     .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson"))
     .to("cache://TestCache1")
   }
};

Example 3: Deleting existing keys in a cache

Code Block


RouteBuilder builder = new RouteBuilder() {
    public void configure() {
     from("direct:start")
     .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_DELETE))
     .setHeader(CacheConstants.CACHE_KEY", constant("Ralph_Waldo_Emerson"))
     .to("cache://TestCache1")
   }
};

Example 4: Deleting all existing keys in a cache

Code Block


RouteBuilder builder = new RouteBuilder() {
    public void configure() {
     from("direct:start")
     .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_DELETEALL))
     .to("cache://TestCache1");
    }
};

Example 5: Notifying any changes registering in a Cache to Processors and other Producers

Code Block


RouteBuilder builder = new RouteBuilder() {
    public void configure() {
     from("cache://TestCache1")
     .process(new Processor() {
        public void process(Exchange exchange)
               throws Exception {
           String operation = (String) exchange.getIn().getHeader(CacheConstants.CACHE_OPERATION);
           String key = (String) exchange.getIn().getHeader(CacheConstants.CACHE_KEY);
           Object body = exchange.getIn().getBody();
           // Do something
        }
     })
   }
};

Example 6: Using Processors to selectively replace payload with cache values

Code Block


RouteBuilder builder = new RouteBuilder() {
   public void configure() {
     //Message Body Replacer
     from("cache://TestCache1")
     .filter(header(CacheConstants.CACHE_KEY).isEqualTo("greeting"))
     .process(new CacheBasedMessageBodyReplacer("cache://TestCache1","farewell"))
     .to("direct:next");

    //Message Token replacer
    from("cache://TestCache1")
    .filter(header(CacheConstants.CACHE_KEY).isEqualTo("quote"))
    .process(new CacheBasedTokenReplacer("cache://TestCache1","novel","#novel#"))
    .process(new CacheBasedTokenReplacer("cache://TestCache1","author","#author#"))
    .process(new CacheBasedTokenReplacer("cache://TestCache1","number","#number#"))
    .to("direct:next");

    //Message XPath replacer
    from("cache://TestCache1").
    .filter(header(CacheConstants.CACHE_KEY).isEqualTo("XML_FRAGMENT"))
    .process(new CacheBasedXPathReplacer("cache://TestCache1","book1","/books/book1"))
    .process (new CacheBasedXPathReplacer("cache://TestCache1","book2","/books/book2"))
    .to("direct:next");
   }
};

Example 7: Getting an entry from the Cache

Code Block


from("direct:start")
    // Prepare headers
    .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_GET))
    .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson")).
    .to("cache://TestCache1").
    // Check if entry was not found
    .choice().when(header(CacheConstants.CACHE_ELEMENT_WAS_FOUND).isNull()).
        // If not found, get the payload and put it to cache
        .to("cxf:bean:someHeavyweightOperation").
        .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_ADD))
        .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson"))
        .to("cache://TestCache1")
    .end()
    .to("direct:nextPhase");

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Note: The CHECK command tests existence of an entry in the cache but doesn't place a message in the body.

Code Block


from("direct:start")
    // Prepare headers
    .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_CHECK))
    .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson")).
    .to("cache://TestCache1").
    // Check if entry was not found
    .choice().when(header(CacheConstants.CACHE_ELEMENT_WAS_FOUND).isNull()).
        // If not found, get the payload and put it to cache
        .to("cxf:bean:someHeavyweightOperation").
        .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_ADD))
        .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson"))
        .to("cache://TestCache1")
    .end();

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Here's a snippet on how to expose them via JMX in a Spring application context:

Code Block

	xml
	xml


<bean id="ehCacheManagementService" class="net.sf.ehcache.management.ManagementService" init-method="init" lazy-init="false">
  <constructor-arg>
    <bean class="net.sf.ehcache.CacheManager" factory-method="getInstance"/>
  </constructor-arg>
  <constructor-arg>
    <bean class="org.springframework.jmx.support.JmxUtils" factory-method="locateMBeanServer"/>
  </constructor-arg>
  <constructor-arg value="true"/>
  <constructor-arg value="true"/>
  <constructor-arg value="true"/>
  <constructor-arg value="true"/>
</bean>

Of course you can do the same thing in straight Java:

Code Block

	java
	java


ManagementService.registerMBeans(CacheManager.getInstance(), mbeanServer, true, true, true, true);

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Child pages

Versions Compared

Old Version 24

New Version Current

Key

Cache Component

URI format

Options

Cache Component options

Sending/Receiving Messages to/from the cache

Message Headers up to Camel 2.7

Sending/Receiving Messages to/from the cache

Message Headers up to Camel 2.7

Message Headers Camel 2.8+

Cache Producer

Example 1: Configuring the cache

Example 2: Adding keys to the cache

Example 2: Updating existing keys in a cache

Example 3: Deleting existing keys in a cache

Example 4: Deleting all existing keys in a cache

Example 5: Notifying any changes registering in a Cache to Processors and other Producers

Example 6: Using Processors to selectively replace payload with cache values

Example 7: Getting an entry from the Cache