bean:beanID[?options]
Where beanID can be any string which is used to lookup look up the bean in the Registry
Name | Type | Default | Description |
---|---|---|---|
method
|
String
|
null
|
The method name that bean will be invoked. If not provided, Apache Camel will try to pick the method itself. In case of ambiguity an exception is thrown. See Bean Binding for more details. From Camel 2.8 onwards you can specify type qualifiers to pin-point exact method to use for overloaded methods. From Camel 2.9 onwards you can specify parameter values directly in the method syntax. |
cache
|
boolean
|
false
|
If enabled, Apache 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. |
multiParameterArray
|
boolean
|
false
|
Apache Camel 1.5: How to
treat the parameters which are passed from the message body;
if it is true , the In message body should
be an array of parameters. |
You can append query options to the URI in the following format,
?option=value&option=value&...
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, put
the bean in JNDI.
// lets populate the context with the services we need // note that we could just use a spring.xml file to avoid this step JndiContext context = new JndiContext(); context.bind("bye", new SayService("Good Bye!")); CamelContext camelContext = new DefaultCamelContext(context);
Once an endpoint has been registered, you can build routes that use it to process exchanges.
// lets add simple route camelContext.addRoutes(new RouteBuilder() { public void configure() { from("direct:hello").to("bean:bye"); } });
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:
Endpoint endpoint = camelContext.getEndpoint("direct:hello"); ISay proxy = ProxyHelper.createProxy(endpoint, ISay.class); String rc = proxy.say(); assertEquals("Good Bye!", rc);
And the same route using XML DSL:
<route> <from uri="direct:hello"> <to uri="bean:bye"/> </route>
Apache Camel also supports invoking Bean
as an Endpoint. In the route below:
<camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <to uri="myBean"/> <to uri="mock:results"/> </route> </camelContext> <bean id="myBean" class="org.apache.camel.spring.bind.ExampleBean"/>
What happens is that when the exchange is routed to the
myBean
Apache Camel will use the Bean Binding to invoke the bean.
The source for the bean is just a plain POJO:
public class ExampleBean { public String sayHello(String name) { return "Hello " + name + "!"; } }
Apache 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.
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);
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
Apache Camel.
Class component