Caffeine Cache Component

Available as of Camel version 2.20

The caffeine-cache component enables you to perform caching operations using the simple cache from Caffeine.

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

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

URI format

caffeine-cache://cacheName[?options]

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

Options

The Caffeine Cache component supports 2 options, which are listed below.

Name Description Default Type

configuration (advanced)

Sets the global component configuration

CaffeineConfiguration

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 Caffeine Cache endpoint is configured using URI syntax:

caffeine-cache:cacheName

with the following path and query parameters:

Path Parameters (1 parameters):

Name Description Default Type

cacheName

Required the cache name

String

Query Parameters (19 parameters):

Name Description Default Type

createCacheIfNotExist (common)

Configure if a cache need to be created if it does exist or can’t be pre-configured.

true

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

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

action (producer)

To configure the default cache action. If an action is set in the message header, then the operation from the header takes precedence.

String

cache (producer)

To configure an already instantiated cache to be used

Cache

cacheLoader (producer)

To configure a CacheLoader in case of a LoadCache use

CacheLoader

evictionType (producer)

Set the eviction Type for this cache

SIZE_BASED

EvictionType

expireAfterAccessTime (producer)

Set the expire After Access Time in case of time based Eviction (in seconds)

300

int

expireAfterWriteTime (producer)

Set the expire After Access Write in case of time based Eviction (in seconds)

300

int

initialCapacity (producer)

Set the initial Capacity for the cache

10000

int

key (producer)

To configure the default action key. If a key is set in the message header, then the key from the header takes precedence.

Object

maximumSize (producer)

Set the maximum size for the cache

10000

int

removalListener (producer)

Set a specific removal Listener for the cache

RemovalListener

statsCounter (producer)

Set a specific Stats Counter for the cache stats

StatsCounter

statsEnabled (producer)

To enable stats on the cache

false

boolean

keyType (advanced)

The cache key type, default java.lang.Object

java.lang.Object

String

synchronous (advanced)

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

false

boolean

valueType (advanced)

The cache value type, default java.lang.Object

java.lang.Object

String

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-caffeine-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 17 options, which are listed below.

Name Description Default Type

camel.component.caffeine-cache.configuration.action

To configure the default cache action. If an action is set in the message header, then the operation from the header takes precedence.

String

camel.component.caffeine-cache.configuration.cache

To configure an already instantiated cache to be used

Cache

camel.component.caffeine-cache.configuration.cache-loader

To configure a CacheLoader in case of a LoadCache use

CacheLoader

camel.component.caffeine-cache.configuration.create-cache-if-not-exist

Configure if a cache need to be created if it does exist or can’t be pre-configured.

true

Boolean

camel.component.caffeine-cache.configuration.eviction-type

Set the eviction Type for this cache

EvictionType

camel.component.caffeine-cache.configuration.expire-after-access-time

Set the expire After Access Time in case of time based Eviction (in seconds)

300

Integer

camel.component.caffeine-cache.configuration.expire-after-write-time

Set the expire After Access Write in case of time based Eviction (in seconds)

300

Integer

camel.component.caffeine-cache.configuration.initial-capacity

Set the initial Capacity for the cache

10000

Integer

camel.component.caffeine-cache.configuration.key

To configure the default action key. If a key is set in the message header, then the key from the header takes precedence.

Object

camel.component.caffeine-cache.configuration.key-type

The cache key type, default java.lang.Object

java.lang.Object

String

camel.component.caffeine-cache.configuration.maximum-size

Set the maximum size for the cache

10000

Integer

camel.component.caffeine-cache.configuration.removal-listener

Set a specific removal Listener for the cache

RemovalListener

camel.component.caffeine-cache.configuration.stats-counter

Set a specific Stats Counter for the cache stats

StatsCounter

camel.component.caffeine-cache.configuration.stats-enabled

To enable stats on the cache

false

Boolean

camel.component.caffeine-cache.configuration.value-type

The cache value type, default java.lang.Object

java.lang.Object

String

camel.component.caffeine-cache.enabled

Whether to enable auto configuration of the caffeine-cache component. This is enabled by default.

Boolean

camel.component.caffeine-cache.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

Examples

You can use your cache with the following code:

    @Override
    protected RouteBuilder createRouteBuilder() throws Exception {
        return new RouteBuilder() {
            public void configure() {
                from("direct://start")
                    .toF("caffeine-cache://%s?cache=#cache&action=PUT&key=1", "test")
                    .toF("caffeine-cache://%s?cache=#cache&key=1&action=GET", "test")
                    .log("Test! ${body}")
                    .to("mock:result");
            }
        };
    }

In this way you’ll work always on the same cache in the registry.

Check operation result

Each time you’ll use an operation on the cache you’ll have two different headers to check for status:

CaffeineConstants.ACTION_HAS_RESULT
CaffeineConstants.ACTION_SUCCEEDED