A handler framework is the functionality (framework) for intercepting and adding processing in the JAX-WS engine when a SOAP Message is sent and received. You can add multiple handlers between the Web Service client and Web Service Implementation Class or the Provider Implementation Class, and extend the Web Service functionality.

The following figure shows the flow of processing in the handler framework:

Figure 36-1 Flow of processing in the handler framework

The contents of handler processing differ in each combination of outbound or inbound and request or response. The following table lists the combinations and the processing contents:

Table 36-1 Combinations of outbound or inbound and request or response and the processing contents

Outbound or Inbound	Request or response	Processing contents
Outbound	Request	Indicates that the Web Service client sends the request message. In this processing, distributing the messages means sending the request messages to the Web Service.
	Response	Indicates that the Web Service Implementation Class or the Provider Implementation Class sends the response message. In this processing, distributing the messages means sending the response messages to the Web Service client. The outbound does not work because no response message is sent in the one-way operations.
Inbound	Request	Indicates that the Web Service Implementation Class or the Provider Implementation Class receives the request message. In this processing, distributing the messages means allocating the request messages to the Web Service Implementation Class or the Provider Implementation Class.
	Response	Indicates that the Web Service client receives the response. In this processing, distributing the messages means allocating the response messages to the Web Service client. The inbound does not work as no response message is received in the one-way operations.

You can acquire the message context in the handler. For details about the message context, see 19.2.5 Using a message context.

For details about the architecture of the handler framework, see JAX-WS 2.2 specifications.