[CONF] Apache Camel: Bean (page edited)

confluence Thu, 02 Oct 2008 00:47:32 -0700

Page Edited : CAMEL : Bean

Bean has been edited by James Strachan (Oct 02, 2008).

Content:

Bean Component

The bean: component binds beans to Camel message exchanges.

URI format

bean:someName[?options]

Where someName can be any string which is used to lookup the bean in the Registry

Options

Name	Description	Example	Required?	default value
method	The method name that bean will be inovked	method=someMethod	No	someMethod defines the name of the method to invoke,This will use the Bean Binding to map the message exchange to the bean.
multiParameterArray	New option in 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 the an array of parameters	multiParameterArray=true	No	false

Using

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.xml; or if you don't use Spring then 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 Camel routes that use it to process exchanges.

// lets add simple route
camelContext.addRoutes(new RouteBuilder() {
    public void configure() {
        from("direct:hello").to("pojo: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);

Bean Binding

How bean methods are chosen to be invoked (if they are not specified explicitly via the method parameter) and how parameter values are constructed from the Message are all defined by the Bean Binding mechanism which is used througout all of the various Bean Integration mechanisms in Camel.