Caffeine Cache
Since Camel 2.20
Only producer is supported
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>caffeine-cache://cacheName[?options]
You can append query options to the URI in the following
format, ?option=value&option=#beanRef&…
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 Caffeine Cache component supports 17 options, which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
To configure the default cache action. If an action is set in the message header, then the operation from the header takes precedence. |
String |
||
To configure a CacheLoader in case of a LoadCache use. |
CacheLoader |
||
Configure if a cache need to be created if it does exist or can’t be pre-configured. |
true |
boolean |
|
Set the eviction Type for this cache. Enum values:
|
SIZE_BASED |
EvictionType |
|
Set the expire After Access Time in case of time based Eviction (in seconds). |
300 |
int |
|
Set the expire After Access Write in case of time based Eviction (in seconds). |
300 |
int |
|
Set the initial Capacity for the cache. |
10000 |
int |
|
To configure the default action key. If a key is set in the message header, then the key from the header takes precedence. |
Object |
||
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 |
|
Set the maximum size for the cache. |
10000 |
int |
|
Set a specific removal Listener for the cache. |
RemovalListener |
||
Set a specific Stats Counter for the cache stats. |
StatsCounter |
||
To enable stats on the cache. |
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 |
|
Sets the global component configuration. |
CaffeineConfiguration |
||
The cache key type, default java.lang.Object. |
String |
||
The cache value type, default java.lang.Object. |
String |
Endpoint Options
The Caffeine Cache endpoint is configured using URI syntax:
caffeine-cache:cacheName
with the following path and query parameters:
Query Parameters (15 parameters)
| Name | Description | Default | Type |
|---|---|---|---|
To configure the default cache action. If an action is set in the message header, then the operation from the header takes precedence. |
String |
||
To configure a CacheLoader in case of a LoadCache use. |
CacheLoader |
||
Configure if a cache need to be created if it does exist or can’t be pre-configured. |
true |
boolean |
|
Set the eviction Type for this cache. Enum values:
|
SIZE_BASED |
EvictionType |
|
Set the expire After Access Time in case of time based Eviction (in seconds). |
300 |
int |
|
Set the expire After Access Write in case of time based Eviction (in seconds). |
300 |
int |
|
Set the initial Capacity for the cache. |
10000 |
int |
|
To configure the default action key. If a key is set in the message header, then the key from the header takes precedence. |
Object |
||
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 |
|
Set the maximum size for the cache. |
10000 |
int |
|
Set a specific removal Listener for the cache. |
RemovalListener |
||
Set a specific Stats Counter for the cache stats. |
StatsCounter |
||
To enable stats on the cache. |
false |
boolean |
|
The cache key type, default java.lang.Object. |
String |
||
The cache value type, default java.lang.Object. |
String |
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")
.to("caffeine-cache://cache?action=PUT&key=1")
.to("caffeine-cache://cache?key=1&action=GET")
.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_SUCCEEDEDSpring Boot Auto-Configuration
When using caffeine-cache 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-caffeine-starter</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>The component supports 36 options, which are listed below.