Spring-WS provides a client-side Web service API that allows for consistent, XML-driven access to Web services. It also allows for use of marshallers and unmarshallers. The package org.springframework.ws.client.core provides the core functionality for using the client-side access API. It contains template classes that simplifies the use of Web services, much like the JdbcTemplate does for JDBC. The design principle common to Spring template classes is to provide helper methods to perform common operations and for more sophisticated usage, delegate the essence of the processing task to user implemented callback interfaces. The Web service template follows the same design. The classes offer various convenience methods for the sending and receiving of XML messages, marshalling objects to XML before sending, and allows for multiple transports,

The WebServiceTemplate is the core class for client-side Web service access in Spring-WS. It contains methods for sending Source objects, and receiving response messages as either Source or Result. Additionally, it can marshal objects to XML before sending them across a transport, and unmarshal the response XML into an object again.

The WebServiceTemplate requires a reference to a MessageSender. The message sender is responsible for sending the XML message across a transport layer. There are two implementations of the MessageSender interface for sending messages via HTTP. The simplest implementation is the HttpUrlConnectionMessageSender, which uses the facilities provided by Java SE itself. The alternative is the CommonsHttpMessageSender, which uses the Jakarta Commons HttpClient. Use the latter if you need more advanced and easy-to-use functionality. Both HTTP message senders require an URL to be set using the url property.

In addition to a message sender, the WebServiceTemplate requires a Web service message factory. As explained in , there are two message factories for SOAP: SaajSoapMessageFactory and AxiomSoapMessageFactory.