Consuming Services – the Spring Web Service Client

There is a downloadable zipped Eclipse project at the end of this post.

Having created a sample (mail) web service some posts ago, we would like to have a client consuming this service.

With Spring Web Services, this can easily be done by using the ubiquitous Template Pattern and, in this special case, the WebServiceTemplate . As the project structure can be downloaded, only the two important snippets are shown here:

The application-config.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">

    <bean id="mailclient" class="de.mail.MailClient">
    	<property name="webServiceTemplate" ref="webServiceTemplate"/>
    </bean>

    <bean id="messageFactory" class="org.springframework.ws.soap.saaj.SaajSoapMessageFactory"/>

    <bean id="webServiceTemplate" class="org.springframework.ws.client.core.WebServiceTemplate">
        <constructor-arg ref="messageFactory"/>
        <property name="marshaller" ref="marshaller"/>
        <property name="unmarshaller" ref="marshaller"/>
        <property name="defaultUri" value="http://localhost:8080/mailservice"/>
    </bean>

    <bean id="marshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
		<property name="classesToBeBound">
			<list>
				<value>org.mail.mailschema.MailRequest</value>
				<value>org.mail.mailschema.MailResponse</value>
			</list>
		</property>
	</bean>

</beans>

and the actual Web Service client:

package de.mail;

import org.mail.mailschema.MailRequest;
import org.mail.mailschema.MailResponse;
import org.springframework.ws.client.core.WebServiceTemplate;

public class MailClient {

	private WebServiceTemplate webServiceTemplate;

	public void setWebServiceTemplate(WebServiceTemplate webServiceTemplate) {
		this.webServiceTemplate = webServiceTemplate;
	}

	public boolean send(String user, String password, String from, String to, String subject, String content) {
		MailRequest request = new MailRequest();
		request.setFrom(from);
		request.setTo(to);
		request.setUser(user);
		request.setPassword(password);
		request.setContent(content);
		request.setSubject(subject);
		return ((MailResponse)webServiceTemplate.marshalSendAndReceive(request)).isResult();
	}

}

The servlet sample is not shown, since it is just for demonstration and not a nice piece of code. However, it exemplifies some Spring antipatterns, because DI is not used and the servlet is not Springified at all. But it’s only a sample showing how to use the Web Service client.
By deploying the servlet (or using mvn jetty:run again), a mail can be send by calling http://server/mailwebapp/Mailer?user=USER&password=PASSWORD&to=RECIPIENT@BLA.DE&from=me&subject=SUBJECT&content=MAILTEXT
But the actual code could be much nicer (also, it is definitely not safe – just a counter and a whitelist is added to prevent immediate abuse )

Sample Mail Web Service client project:

Instructions:

1. Download the wsclient-sample
2. Download the mailwebapp-sample
3. Download the maildatabinding

If correctly imported as Eclipse projects, the dependencies should be automatically resolved.
The mailwebapp can be deployed as a usual Web application which uses the Web Service client to call the Mail Web Service, which must be already deployed (compare the Spring Web Service post).