/gs-consuming-web-service

Consuming a SOAP web service :: Learn how to create a client that consumes a WSDL-based service

Primary LanguageJava

Table of Contents

This guide walks you through the process of consuming a SOAP-based web service with Spring.

What you’ll build

You will build a client that fetches country data data from a remote, WSDL-based web service using SOAP. You can find out more about the country service, and run the service yourself by following this guide.

The service provides country data. You will be able to query data about a country based on its name.

What you’ll need

Note
 If you read Producing a SOAP web service, you might be wondering why this guide doesn’t use spring-boot-starter-ws? That Spring Boot starter is only for server-side web services. That starter brings on board things like embedded Tomcat, which isn’t need to make a web call.

Run the target web service locally

Follow the steps in the companion guide, or just clone the repository and run the service (e.g. using mvn spring-boot:run) from its complete directory. You can verify that is working by visiting http://localhost:8080/ws/countries.wsdl in your browser.

Generate domain objects based on a WSDL

The interface to a SOAP web service is captured in a WSDL. JAXB provides an easy means to generate Java classes from a WSDL (or rather: the XSD contained in the <Types/> section of the WSDL). The WSDL for the country service can be found at http://localhost:8080/ws/countries.wsdl.

To generate Java classes from the WSDL in maven, you need the following plugin setup:

link:complete/pom.xml[role=include]

This setup will generate classes for the WSDL found at the specified URL, putting those classes in the hello.wsdl package.

To do the same with gradle, you will need the following in your build file:

link:complete/build.gradle[role=include]

As gradle does not have a JAXB plugin (yet), it involves an ant task, which makes it a bit more complex than in maven.

In both cases, the JAXB domain object generation process has been wired into the build tool’s lifecycle so there are no extra steps to run.

Create a country service client

To create a web service client, you simply have to extend the WebServiceGatewaySupport class and code your operations:

src/main/java/hello/CountryClient.java

link:complete/src/main/java/hello/CountryClient.java[role=include]

The client contains one method: getCountry which does the actual SOAP exchange.

In this method, both the GetCountryRequest and the GetCountryResponse classes are derived from the WSDL and were generated in the JAXB generation process described in the previous step. It creates the GetCountryRequest request object and sets it up with the country parameter (the name of the country). After printing out the country name, it uses the WebServiceTemplate supplied by the WebServiceGatewaySupport base class to do the actual SOAP exchange. It passes the GetCountryRequest request object, as well as a SoapActionCallback to pass on a SOAPAction header with the request, as the WSDL described that it needed this header in the <soap:operation/> elements. It casts the response into a GetCountryResponse object, which is then returned.

Configuring web service components

Spring WS uses Spring Framework’s OXM module which has the Jaxb2Marshaller to serialize and deserialize XML requests.

src/main/java/hello/CountryConfiguration.java

link:complete/src/main/java/hello/CountryConfiguration.java[role=include]

The marshaller is pointed at the collection of generated domain objects and will use them to both serialize and deserialize between XML and POJOs.

The countryClient is created and configured with the URI of the country service shown up above. It is also configured to use the JAXB marshaller.

Make the application executable

This application is packaged up to run from the console and retrieve the data for a given country name:

src/main/java/hello/Application.java

link:complete/src/main/java/hello/Application.java[role=include]

The main() method defers to the SpringApplication helper class, providing CountryConfiguration.class as an argument to its run() method. This tells Spring to read the annotation metadata from CountryConfiguration and to manage it as a component in the Spring application context.

Note
 This application is hard coded to look up symbol 'MSFT' which correspond to Microsoft Corporation. Towards the end of this guide, you’ll see how to plug in a different symbol without editing the code.

Logging output is displayed. The service should be up and running within a few seconds.

Requesting country data for Spain

<getCountryRequest><name>Spain</name>...</getCountryRequest>

You can plug in a different country by typing java -jar build/libs/gs-consuming-web-service-0.1.0.jar Poland

Requesting location for Poland

<getCountryRequest><name>Poland</name>...</getCountryRequest>

Summary

Congratulations! You’ve just developed a client to consume a SOAP-based web service with Spring.

See Also

The following guides may also be helpful: