http://opensourcesoftwareandme.blogspot.hk/2012/12/demystifying-apache-cxf-restful-hello.html
The first post of this how-to series showed you what it takes to expose a Hello World application as a SOAP over HTTP Web Service using CXF. For this post, I'll show you how to expose the same app as a RESTful service.
In the Java world, we use JAX-RS for mapping a class to a RESTful service. Giving a RESTful interface to our Hello World app is just a matter of adding JAX-RS annotations to HelloWorldImpl:
package org.opensourcesoftwareandme;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
"/helloWorld")
public class HelloWorldImpl
@GET
@Produces( "text/html")
@Path( "sayHi/{text}")
public String sayHi( @PathParam( "text") String text) {
return "Hello " +
}
}
view raw
HelloWorldImpl.java hosted with ❤ by
GitHub
In the class, I tell the JAX-RS provider (i.e., CXF):
- HelloWorldImpl is a resource available on the URL relative path "/helloWorld" (@Path("/helloWorld")).
- the HTTP reply sent back to the client should have the Content-Type set to "text/hml" (@Produces).
- sayHi is to be called when the HTTP request is a GET and the relative path is "/helloWorld/sayHi/" + [variable] (@Path("sayHi/{text}")).
- to bind the URL parameter with the method argument text (@PathParam).
As in the previous how-to, I'm going to deploy the app onto an embedded Jetty server instead of deploying it onto a standalone web container:
package org.opensourcesoftwareandme;
import org.apache.cxf.jaxrs.JAXRSServerFactoryBean;
import javax.ws.rs.ext.RuntimeDelegate;
public class Server
public static void main( String args[]) throws Exception
JAXRSServerFactoryBean jaxrsServerFactory = RuntimeDelegate .getInstance() .createEndpoint( new HelloWorldApp(), JAXRSServerFactoryBean .class);
.setAddress( "http://localhost:9000");
org.apache.cxf.endpoint.Server server = jaxrsServerFactory .create();
.start();
System .out .println( "Server started...");
Thread .sleep( 5 * 60 * 1000);
System .out .println( "Server stopping...");
.stop();
System .exit( 0);
}
}
view raw Server.java hosted with ❤ by GitHub
RuntimeDelegate.getInstance().createEndpoint(...) is a JAX-RS method that returns an unpublished endpoint. It takes in:
- a class responsible for configuring and launching the web server. This class differs across JAX-RS providers. CXF expects this class to be JAXRSServerFactoryBean.
- an object that extends Application. This user-defined class must return JAX-RS annotated classes responsible for processing client requests. For us, this means returning HelloWorldImpl:
package org.opensourcesoftwareandme;
import javax.ws.rs.core.Application;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
public class HelloWorldApp extends Application
public Set<Class<?>> getClasses() {
Set<Class<?>> classes = new HashSet<Class<?>>();
.add( HelloWorldImpl .class);
return
}
}
view raw HelloWorldApp.java hosted with ❤ by GitHub
Back to our
Server.java file, I tell the endpoint to bind the server to the URL
http://localhost:9000. Then, from the endpoint, I create a
org.apache.cxf.endpoint.Server object and invoke
start(...) to publish the service. Note that, underneath,
org.apache.cxf.endpoint.Server is a configured Jetty.
Before testing the service, I add the required CXF libraries to the Java classpath by declaring them as dependencies in project's POM :
...
dependencies>
dependency>
groupId>org.apache.cxf</ groupId>
artifactId>cxf-rt-frontend-jaxrs</ artifactId>
version> ${cxf.version}</ version>
dependency>
dependency>
groupId>org.apache.cxf</ groupId>
artifactId>cxf-rt-transports-http-jetty</ artifactId>
version> ${cxf.version}</ version>
dependency>
dependencies>
...
view raw pom.xml hosted with ❤ by GitHub
If you compare this POM with the POM of the first how-to, you'll note that now I've swapped the JAX-WS frontend with the JAX-RS one.
All that is left is to run the server with the following Maven commands:
; mvn exec:java -Dexec.mainClass= "org.opensourcesoftwareandme.Server"
view raw run.sh hosted with ❤ by GitHub
Once the server is up, accessing via your browser the URL http://localhost:9000/helloWorld/sayHi/Ricston
