Basic Configuration

Overview

The basic requirements for configuring a poller endpoint are straightforward. You need to supply the following information:

the endpoint's name
the endpoint's service name
the file or directory to be monitored
the ESB endpoint to which the resulting messages will be sent

All of this information is provided using attributes of the poller element.

Identifying the endpoint

All endpoints in the ESB need to have a unique identity. An endpoint's identity is made up of two pieces:

a service name
an endpoint name

Table 2.1 describes the attributes used to identify a poller endpoint.

Table 2.1. Attributes for Identifying a Poller Endpoint

Name	Description
`service`	Specifies the service name of the endpoint. This value must be a valid QName and does not need to be unique across the ESB.
`endpoint`	Specifies the name of the endpoint. This value is a simple string. It must be unique among all of the endpoints associated with a given service name.

Specifying the message source

You specify the location the poller endpoint looks for new messages using the poller element's file attribute. This attribute takes a URI that identifies a location on the file system.

If you want the endpoint to poll a specific file you use the standard file:location URI. If you do not use the file prefix, the endpoint will assume the URI specifies a directory on the file system and will consume all valid XML files placed in the specified directory.

For example, the URI file:inbox tells the endpoint to poll for a file called inbox. The URI inbox instructs the endpoint to poll the directory inbox.

	Important
	Relative URIs are resolved from the directory in which the FUSE ESB container was started.

Specifying the target endpoint

There are a number of attributes available for configuring the endpoint to which the generated messages are sent. The poller endpoint will determine the target endpoint in the following manner:

If you explicitly specify an endpoint using both the targetService attribute and the targetEndpoint attribute, the ESB will use that endpoint.
The targetService attribute specifies the QName of a service deployed into the ESB. The targetEndpoint attribute specifies the name of an endpoint deployed by the service specified by the targetService attribute.
If you only specify a value for the targetService attribute, the ESB will attempt to find an appropriate endpoint on the specified service.
If you do not specify a service name or an endpoint name, you must specify an the name of an interface that can accept the message using the targetInterface attribute. The ESB will attempt to locate an endpoint that implements the specified interface and direct the messages to it.
Interface names are specified as QNames. They correspond to the value of the name attribute of either a WSDL 1.1 serviceType element or a WSDL 2.0 interface element.

	Important
	If you specify values for more than one of the target attributes, the poller endpoint will use the most specific information.

Example

Example 2.1 shows the configuration for a simple poller endpoint.

Example 2.1. Simple Poller Endpoint

<beans xmlns:file="http://servicemix.apache.org/file/1.0"
	       xmlns:foo="http://servicemix.org/demo/">

  <file:poller service="foo:filePoller"
               endpoint="filePoller"
               targetService="foo:fileSender" 
               file="file:inbox/test.xml" />
  ...
</beans>