Class
Since Camel 2.4
Only producer is supported
The Class component binds beans to Camel message exchanges. It works in the same way as the Bean component but instead of looking up beans from a Registry it creates the bean based on the class name.
URI format
class:className[?options]
Where className is the fully qualified class name to create and use as bean.
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 Class component supports 4 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
cache (producer) |
Deprecated Use singleton option instead. |
true |
Boolean |
lazyStartProducer (producer) |
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. |
boolean |
|
scope (producer) |
Scope of bean. When using singleton scope (default) the bean is created or looked up only once and reused for the lifetime of the endpoint. The bean should be thread-safe in case concurrent threads is calling the bean at the same time. When using request scope the bean is created or looked up once per request (exchange). This can be used if you want to store state on a bean while processing a request and you want to call the same bean instance multiple times while processing the request. The bean does not have to be thread-safe as the instance is only called from the same request. When using delegate scope, then the bean will be looked up or created per call. However in case of lookup then this is delegated to the bean registry such as Spring or CDI (if in use), which depends on their configuration can act as either singleton or prototype scope. so when using prototype then this depends on the delegated registry. Enum values:
|
Singleton |
BeanScope |
autowiredEnabled (advanced) |
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 |
Endpoint Options
The Class endpoint is configured using URI syntax:
class:beanName
with the following path and query parameters:
Path Parameters (1 parameters)
Name | Description | Default | Type |
---|---|---|---|
beanName (common) |
Required Sets the name of the bean to invoke. |
String |
Query Parameters (5 parameters)
Name | Description | Default | Type |
---|---|---|---|
cache (common) |
Deprecated Use scope option instead. |
Boolean |
|
method (common) |
Sets the name of the method to invoke on the bean. |
String |
|
scope (common) |
Scope of bean. When using singleton scope (default) the bean is created or looked up only once and reused for the lifetime of the endpoint. The bean should be thread-safe in case concurrent threads is calling the bean at the same time. When using request scope the bean is created or looked up once per request (exchange). This can be used if you want to store state on a bean while processing a request and you want to call the same bean instance multiple times while processing the request. The bean does not have to be thread-safe as the instance is only called from the same request. When using prototype scope, then the bean will be looked up or created per call. However in case of lookup then this is delegated to the bean registry such as Spring or CDI (if in use), which depends on their configuration can act as either singleton or prototype scope. so when using prototype then this depends on the delegated registry. Enum values:
|
Singleton |
BeanScope |
lazyStartProducer (producer) |
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. |
boolean |
|
parameters (advanced) |
Used for configuring additional properties on the bean. |
Map |
Using
You simply use the class component just as the Bean
component but by specifying the fully qualified classname instead.
For example to use the MyFooBean
you have to do as follows:
from("direct:start").to("class:org.apache.camel.component.bean.MyFooBean").to("mock:result");
You can also specify which method to invoke on the MyFooBean
, for
example hello
:
from("direct:start").to("class:org.apache.camel.component.bean.MyFooBean?method=hello").to("mock:result");
Setting properties on the created instance
In the endpoint uri you can specify properties to set on the created
instance, for example if it has a setPrefix
method:
from("direct:start")
.to("class:org.apache.camel.component.bean.MyPrefixBean?bean.prefix=Bye")
.to("mock:result");
And you can also use the #
syntax to refer to properties to be looked
up in the Registry.
from("direct:start")
.to("class:org.apache.camel.component.bean.MyPrefixBean?bean.cool=#foo")
.to("mock:result");
Which will lookup a bean from the Registry with the
id foo
and invoke the setCool
method on the created instance of the
MyPrefixBean
class.
See more details at the Bean component as the class component works in much the same way. |
Spring Boot Auto-Configuration
When using bean 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-bean-starter</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
The component supports 13 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
camel.component.bean.autowired-enabled |
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 |
camel.component.bean.enabled |
Whether to enable auto configuration of the bean component. This is enabled by default. |
Boolean |
|
camel.component.bean.lazy-start-producer |
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 |
camel.component.bean.scope |
Scope of bean. When using singleton scope (default) the bean is created or looked up only once and reused for the lifetime of the endpoint. The bean should be thread-safe in case concurrent threads is calling the bean at the same time. When using request scope the bean is created or looked up once per request (exchange). This can be used if you want to store state on a bean while processing a request and you want to call the same bean instance multiple times while processing the request. The bean does not have to be thread-safe as the instance is only called from the same request. When using delegate scope, then the bean will be looked up or created per call. However in case of lookup then this is delegated to the bean registry such as Spring or CDI (if in use), which depends on their configuration can act as either singleton or prototype scope. so when using prototype then this depends on the delegated registry. |
BeanScope |
|
camel.component.class.autowired-enabled |
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 |
camel.component.class.enabled |
Whether to enable auto configuration of the class component. This is enabled by default. |
Boolean |
|
camel.component.class.lazy-start-producer |
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 |
camel.component.class.scope |
Scope of bean. When using singleton scope (default) the bean is created or looked up only once and reused for the lifetime of the endpoint. The bean should be thread-safe in case concurrent threads is calling the bean at the same time. When using request scope the bean is created or looked up once per request (exchange). This can be used if you want to store state on a bean while processing a request and you want to call the same bean instance multiple times while processing the request. The bean does not have to be thread-safe as the instance is only called from the same request. When using delegate scope, then the bean will be looked up or created per call. However in case of lookup then this is delegated to the bean registry such as Spring or CDI (if in use), which depends on their configuration can act as either singleton or prototype scope. so when using prototype then this depends on the delegated registry. |
BeanScope |
|
camel.language.bean.enabled |
Whether to enable auto configuration of the bean language. This is enabled by default. |
Boolean |
|
camel.language.bean.scope |
Scope of bean. When using singleton scope (default) the bean is created or looked up only once and reused for the lifetime of the endpoint. The bean should be thread-safe in case concurrent threads is calling the bean at the same time. When using request scope the bean is created or looked up once per request (exchange). This can be used if you want to store state on a bean while processing a request and you want to call the same bean instance multiple times while processing the request. The bean does not have to be thread-safe as the instance is only called from the same request. When using prototype scope, then the bean will be looked up or created per call. However in case of lookup then this is delegated to the bean registry such as Spring or CDI (if in use), which depends on their configuration can act as either singleton or prototype scope. So when using prototype scope then this depends on the bean registry implementation. |
Singleton |
String |
camel.language.bean.trim |
Whether to trim the value to remove leading and trailing whitespaces and line breaks |
true |
Boolean |
camel.component.bean.cache |
Deprecated Use singleton option instead. |
true |
Boolean |
camel.component.class.cache |
Deprecated Use singleton option instead. |
true |
Boolean |