Chapter 40. Bean Component
Available as of Camel version 1.0
The bean: component binds beans to Camel message exchanges.
40.1. URI format
Where beanID can be any string which is used to look up the bean in the Registry
The Bean component has no options.
The Bean endpoint is configured using URI syntax:
with the following path and query parameters:
40.2.1. Path Parameters (1 parameters):
Required Sets the name of the bean to invoke
40.2.2. Query Parameters (5 parameters):
Sets the name of the method to invoke on the bean
If enabled, Camel will cache the result of the first Registry look-up. Cache can be enabled if the bean in the Registry is defined as a singleton scope.
Deprecated How to treat the parameters which are passed from the message body; if it is true, the message body should be an array of parameters. Note: This option is used internally by Camel, and is not intended for end users to use. Deprecation note: This option is used internally by Camel, and is not intended for end users to use.
Used for configuring additional properties on the bean
Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).
You can append query options to the URI in the following format,
The object instance that is used to consume messages must be explicitly registered with the Registry. For example, if you are using Spring you must define the bean in the Spring configuration,
spring.xml; or if you don’t use Spring, by registering the bean in JNDI.
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Once an endpoint has been registered, you can build Camel routes that use it to process exchanges.
A bean: endpoint cannot be defined as the input to the route; i.e. you cannot consume from it, you can only route from some inbound message Endpoint to the bean endpoint as output. So consider using a direct: or queue: endpoint as the input.
You can use the
createProxy() methods on ProxyHelper to create a proxy that will generate BeanExchanges and send them to any endpoint:
And the same route using Spring DSL:
<route> <from uri="direct:hello"> <to uri="bean:bye"/> </route>
40.4. Bean as endpoint
Camel also supports invoking Bean as an Endpoint. In the route below:
What happens is that when the exchange is routed to the
myBean Camel will use the Bean Binding to invoke the bean.
The source for the bean is just a plain POJO:
Camel will use Bean Binding to invoke the
sayHello method, by converting the Exchange’s In body to the
String type and storing the output of the method on the Exchange Out body.
40.5. Java DSL bean syntax
Java DSL comes with syntactic sugar for the Bean component. Instead of specifying the bean explicitly as the endpoint (i.e.
to("bean:beanName")) you can use the following syntax:
// Send message to the bean endpoint // and invoke method resolved using Bean Binding. from("direct:start").beanRef("beanName"); // Send message to the bean endpoint // and invoke given method. from("direct:start").beanRef("beanName", "methodName");
Instead of passing name of the reference to the bean (so that Camel will lookup for it in the registry), you can specify the bean itself:
// Send message to the given bean instance. from("direct:start").bean(new ExampleBean()); // Explicit selection of bean method to be invoked. from("direct:start").bean(new ExampleBean(), "methodName"); // Camel will create the instance of bean and cache it for you. from("direct:start").bean(ExampleBean.class);
40.6. Bean Binding
How bean methods to be invoked are chosen (if they are not specified explicitly through the method parameter) and how parameter values are constructed from the Message are all defined by the Bean Binding mechanism which is used throughout all of the various Bean Integration mechanisms in Camel.
40.7. See Also
- Configuring Camel
- Getting Started
- Class component
- Bean Binding
- Bean Integration