Implementing a SOAP client with CXF using Play Framework 2.x

December 21, 2015

TL;DR: if you want to skip the tutorial, all code is directly available on GitHub: https://github.com/damienbeaufils/soap-client-with-cxf-using-play

EDIT June 2016: code on my GitHub repository updated for Play Framework 2.5! Play 2.4 version is still available here.

I was working on a new client product, and I had to plug a web application built with Play Framework (and then sbt) to SOAP web services. How to do it?

The need: be able to generate Java classes from one or many WSDL files, and use those classes with Play 2.4 dependency injection (which use Guice as implementation).

The issue: no out-of-the-box SOAP support on Play.

The good news: there is an official plugin from Typesafe which answer the need: play-soap-sbt. It promises a reactive implementation of SOAP web services calls from your application.

The bad news: this plugin is a part of the Typesafe Reactive Plateform suite, and you have to pay an unknown amount (I didn’t found any value on the website) to be able to use this plugin in your application.

Coming from the Java/Groovy world, I often used Spring framework. When I had to use SOAP in an application, I used CXF most of the time, which works perfectly with Spring. So I asked myself how to use CXF with Play?

I didn’t found any miracle answer on the web, so I built a custom solution, inspired mainly by play-cxf. So here is a tutorial, step by step, to implement a SOAP client with CXF 3.1.x using Play Framework 2.4.x:

Step 1: create a new Play application with activator

Optional step if you already have an existing application.

# cf. https://www.playframework.com/documentation/2.4.x/NewApplication
activator new soap-client-with-cxf-using-play play-java

Step 2: download a WSDL and store it in the project

I use for this tutorial the GlobalWeather SOAP web service. Once the WSDL downloaded, the file is saved in the conf/wsdls folder:

cd soap-client-with-cxf-using-play/conf
mkdir wsdls
wget http://www.webservicex.net/globalweather.asmx?WSDL -O wsdls/globalweather.wsdl

Step 3: add the sbt-cxf-wsdl2java plugin

In the project/plugins.sbt file:

resolvers += "Sonatype Repository" at "https://oss.sonatype.org/content/groups/public"
addSbtPlugin("com.ebiznext.sbt.plugins" % "sbt-cxf-wsdl2java" % "0.1.4")

Step 4: add CXF required dependencies

In the build.sbt file:

val cxfVersion: String = "3.1.4"
 
libraryDependencies ++= Seq(
  ...
  "org.apache.cxf" % "cxf-rt-frontend-jaxws" % cxfVersion,
  "org.apache.cxf" % "cxf-rt-transports-http" % cxfVersion
)

Step 5: configure the wsdl2java task to automatically generate the classes corresponding to the downloaded WSDL

In the build.sbt file:

// CXF wsdl2java configuration
Seq(cxf.settings: _*)
cxf.cxfVersion := cxfVersion
cxf.wsdls := Seq(
  cxf.Wsdl((resourceDirectory in Compile).value / "wsdls/globalweather.wsdl", Seq("-mark-generated", "-p", "com.global.weather"), "globalweather")
)

Step 6: launch wsdl2java task

activator clean wsdl2java

or

sbt clean wsdl2java

Generated classes should then be found in target/cxf/globalweather folder:

tree target/cxf/globalweather
 
target/cxf/globalweather/
└── com
    └── global
        └── weather
            ├── GetCitiesByCountry.java
            ├── GetCitiesByCountryResponse.java
            ├── GetWeather.java
            ├── GetWeatherResponse.java
            ├── GlobalWeatherHttpGet_GlobalWeatherHttpGet_Client.java
            ├── GlobalWeatherHttpGet.java
            ├── GlobalWeatherHttpPost_GlobalWeatherHttpPost_Client.java
            ├── GlobalWeatherHttpPost.java
            ├── GlobalWeather.java
            ├── GlobalWeatherSoap_GlobalWeatherSoap12_Client.java
            ├── GlobalWeatherSoap_GlobalWeatherSoap_Client.java
            ├── GlobalWeatherSoap.java
            ├── ObjectFactory.java
            └── package-info.java
 
3 directories, 14 files

Step 7: add Spring Context dependency

Generated classes are now in the classpath, but we have to use Spring to be able to instanciate and use CXF JAX-WS client.

libraryDependencies ++= Seq(
  ...
  "org.springframework" % "spring-context" % "4.2.4.RELEASE"
)

Step 8: declare CXF generated JAX-WS client in the Spring context

In the CXF generated sources, an interface with @WebService annotation has been created and we can use it to easily declare the JAX-WS client. In this example, Spring context file is named applicationContext.xml and stored in conf folder:

<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jaxws="http://cxf.apache.org/jaxws" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd http://cxf.apache.org/jaxws http://cxf.apache.org/schemas/jaxws.xsd">
 
    <import resource="classpath*:META-INF/cxf/cxf.xml"/>
 
    <jaxws:client id="globalWeatherSoapClient" serviceClass="com.global.weather.GlobalWeatherSoap" address="${global.weather.host}/globalweather.asmx"/>
 
</beans>

Step 9: configure Play to load Spring context when application starts

For this, it is necessary to create a module, which will programmatically load Spring context, and to declare it in application configuration.

In this example, module is named ApplicationContextBinderModule and stored in app/modules folder:

package modules;
 
import com.google.inject.AbstractModule;
import org.springframework.context.support.ClassPathXmlApplicationContext;
 
public class ApplicationContextBinderModule extends AbstractModule {
 
    @Override
    protected void configure() {
        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
 
        applicationContext.start();
        applicationContext.registerShutdownHook();
    }
 
}

The module is then declared in application configuration. Here in the main configuration file application.conf:

play.modules.enabled += "modules.ApplicationContextBinderModule"

Step 10: configure Play dependency injection (Guice) to be able to load the JAX-WS client with the @Inject annotation

With the Spring context loaded, a bean globalWeatherSoapClient exists, so we have now to tell to Guice which instance to bind when we want to inject a GlobalWeatherSoap dependency:

package modules;
 
import com.global.weather.GlobalWeatherSoap;
import com.google.inject.AbstractModule;
import org.springframework.context.support.ClassPathXmlApplicationContext;
 
public class ApplicationContextBinderModule extends AbstractModule {
 
    @Override
    protected void configure() {
        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
 
        applicationContext.start();
        applicationContext.registerShutdownHook();
 
        // Guice instance binding
        bind(GlobalWeatherSoap.class).toInstance((GlobalWeatherSoap) applicationContext.getBean("globalWeatherSoapClient"));
    }
 
}

Step 11: inject the JAX-WS client to call SOAP web services

Example in a GlobalWeatherController controller:

# Routes
# ~~~~
GET /cities/:country @controllers.GlobalWeatherController.getCities(country: String)
GET /weather/:country/:city @controllers.GlobalWeatherController.getWeather(country: String, city: String)
package controllers;
 
import com.global.weather.GlobalWeatherSoap;
import play.mvc.Controller;
import play.mvc.Result;
 
import javax.inject.Inject;
 
public class GlobalWeatherController extends Controller {
 
    @Inject
    private GlobalWeatherSoap globalWeatherSoapClient;
 
    public Result getCities(String countryName) {
        String cities = globalWeatherSoapClient.getCitiesByCountry(countryName);
        return ok(cities).as("text/xml");
    }
 
    public Result getWeather(String countryName, String cityName) {
        String weather = globalWeatherSoapClient.getWeather(cityName, countryName);
        return ok(weather).as("text/xml");
    }
}

Step 12: run and test!

activator run

or

sbt run

and then

curl http://localhost:9000/cities/France

or

curl http://localhost:9000/weather/France/Cognac

Second request result:

<CurrentWeather>
    <Location>Cognac, France (LFBG) 45-40N 000-19W 31M</Location>
    <Time>Nov 09, 2015 - 07:30 AM EST / 2015.11.09 1230 UTC</Time>
    <Wind> from the SSW (200 degrees) at 7 MPH (6 KT):0</Wind>
    <Visibility> greater than 7 mile(s):0</Visibility>
    <SkyConditions> overcast</SkyConditions>
    <Temperature> 64 F (18 C)</Temperature>
    <DewPoint> 59 F (15 C)</DewPoint>
    <RelativeHumidity> 82%</RelativeHumidity>
    <Pressure> 30.47 in. Hg (1032 hPa)</Pressure>
    <Status>Success</Status>
</CurrentWeather>

Step 13 (bonus): use Play configuration in Spring context

The applicationContext.xml file we use contains only hard-coded values. When we use SOAP web services, we often have several environments (dev vs. prod).

It is possible to load configuration files in Spring context, with PropertySourcesPlaceholderConfigurer, but it is designed to read properties files and not HOCON files, which are used by Play Framework.

So I created a HoconPropertySourcesPlaceholderConfigurer class, which is able to read a *.conf file in order to use it in Spring context with SpEL.

package utils;
 
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.core.env.ConfigurablePropertyResolver;
import org.springframework.util.StringValueResolver;
 
public class HoconPropertySourcesPlaceholderConfigurer extends PropertySourcesPlaceholderConfigurer {
 
    @Override
    protected void processProperties(ConfigurableListableBeanFactory beanFactoryToProcess, ConfigurablePropertyResolver propertyResolver) throws BeansException {
        propertyResolver.setPlaceholderPrefix(this.placeholderPrefix);
        propertyResolver.setPlaceholderSuffix(this.placeholderSuffix);
        propertyResolver.setValueSeparator(this.valueSeparator);
 
        StringValueResolver valueResolver = strVal -> {
            String resolved = ignoreUnresolvablePlaceholders ?
                    propertyResolver.resolvePlaceholders(strVal) :
                    propertyResolver.resolveRequiredPlaceholders(strVal);
            return resolved.equals(nullValue) ? null : StringUtils.replace(resolved, "\"", "");
        };
 
        doProcessProperties(beanFactoryToProcess, valueResolver);
    }
}

The applicationContext.xml file then become:

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:jaxws="http://cxf.apache.org/jaxws"
       xmlns:http-conf="http://cxf.apache.org/transports/http/configuration"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
        http://cxf.apache.org/jaxws http://cxf.apache.org/schemas/jaxws.xsd
        http://cxf.apache.org/transports/http/configuration http://cxf.apache.org/schemas/configuration/http-conf.xsd">
 
    <import resource="classpath*:META-INF/cxf/cxf.xml"/>
 
    <bean class="utils.HoconPropertySourcesPlaceholderConfigurer">
        <!-- Load configuration file defined in config.resource (see https://www.playframework.com/documentation/2.4.x/ProductionConfiguration) -->
        <!-- If no config.resource defined, use application.conf -->
        <property name="location" value="#{systemProperties['config.resource'] ?: 'application.conf'}"/>
    </bean>
 
    <jaxws:client id="globalWeatherSoapClient"
                  serviceClass="com.global.weather.GlobalWeatherSoap"
                  address="${global.weather.host}/globalweather.asmx"/>
 
    <http-conf:conduit name="${global.weather.host}/.*">
        <http-conf:client ConnectionTimeout="${global.weather.connection.timeout}"
                          ReceiveTimeout="${global.weather.response.timeout}"
                          AllowChunking="false"/>
    </http-conf:conduit>
 
</beans>

And in configuration:

# Global weather SOAP client configuration
# ~~~~~
global.weather.host = "http://www.webservicex.net"
global.weather.connection.timeout = 60000
global.weather.response.timeout = 60000

Final code

All the code of this tutorial is available on GitHub: https://github.com/damienbeaufils/soap-client-with-cxf-using-play

Feel free to fork & enjoy!

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