A Client instance is required to build and run client requests to access or consume web resources. In the RESTEasy client class RESTEasyClient.java, create a Client instance from ClientBuilder using the newClient() method as follows:

Client client = ClientBuilder.newClient();

Providers, filters, and features can be configured with the Client object using the register() method. For example, the org.jboss.resteasy.plugins.providers.JaxrsFormProvider.class provider class is registered as follows:

client.register(org.jboss.resteasy.plugins.providers.JaxrsFormProvider.class);

The Client API is used to access a web resource as follows:

The RESTEasyClient.java class is listed as follows:

package org.jboss.resteasy.rest;

import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;

import javax.ws.rs.client.WebTarget;
import javax.ws.rs.core.*;

import org.jboss.resteasy.client.jaxrs.ResteasyClient;

public class RESTEasyClient {
  
  public static void main(String[] args) {
    
    Client client =	ClientBuilder.newClient();
    
    String response = client.target("http://localhost:8080/jboss-resteasy/rest/helloworld").path("text").request("text/plain").get(String.class);
    
    
    System.out.println(response);
  }
  
}

Create a resource class hosted at the /helloworld URI path to test the Client API. Add a resource method at the relative URI path /text to return a Hello message from a name. The resource class HelloWorldResource is listed as follows:

package org.jboss.resteasy.rest;

import javax.ws.rs.GET;
import javax.ws.rs.Produces;
import javax.ws.rs.Path;


@Path("/helloworld")
public class HelloWorldResource {
  
  @GET
  @Produces("text/plain")
  @Path("/text")
  public String getClichedMessage() {
    
    return "Hello John Smith";
  }
  
}

To test the resource class and the client, compile, package, and deploy the jboss-resteasy application to WildFly. We will add the output directory as the WildFly deployments directory to the configuration for the Maven WAR plugin, as shown here:

<plugin>
  <artifactId>maven-war-plugin</artifactId>
  <version>${version.war.plugin}</version>
  <configuration>
    <outputDirectory>C:wildfly-8.1.0.Finalstandalonedeployments</outputDirectory>
    <failOnMissingWebXml>false</failOnMissingWebXml>
  </configuration>
</plugin>

Right-click on pom.xml and select Run As | Maven install, which is shown as follows:

The jboss-resteasy application gets compiled, built, and outputted to the WildFly 8.1 deployments directory is indicated by the BUILD SUCCESS message in the Console, which is shown as follows:

Now, log in to the WildFly 8.1 Administration Console and click on Manage Deployments. The jboss-resteasy.war application should be listed as deployed, which is shown in the following screenshot:

To test the client, right-click on the RESTEasyClient.java class in Project Explorer and select Run As | Java Application, as shown here:

The client application runs to invoke the resource class and produces the output, as shown in the following Console:

To invoke a resource method with parameters, the @QueryParam annotation can be used to bind request parameters to resource method parameters. In a variation of the resource class used in the previous subsection, add a String parameter to the resource method. Annotate the parameter declaration with @QueryParam and set its default value as DefaultValue:

@GET
@Produces("text/plain")
@Path("/text")
public String getClichedMessage(@QueryParam("name") @DefaultValue("John Smith") String name) {
  return "Hello " +name;
}

In the client class, the query parameter can be sent in the request using the queryParam() method as follows:

String response = client.target("http://localhost:8080/jboss-resteasy/rest/helloworld").path("text").queryParam("name", "John Smith").request("text/plain").get(String.class);

Alternatively, the query parameter can be included in the request URI, which is shown as follows:

String response = client.target("http://localhost:8080/jboss-resteasy/rest/helloworld/text?name=John Smith").request("text/plain").get(String.class);

The resource URI can also be built using template parameters. In a variation of HelloWorldResource, specify a template parameter {name} in the @Path annotating the resource method. Bind the template parameter to the resource method parameter using the @PathParam annotation:

@GET
@Produces("text/plain")
@Path("/text/{name}")
public String getClichedMessage(@PathParam("name") String name) {
  return "Hello " +name;
}

In the RESTEasyClient class, include the value for the {name} template parameter in the resource URI as follows:

String response = client.target("http://localhost:8080/jboss-resteasy/rest/helloworld/text/John Smith").request("text/plain").get(String.class);

Redeploy the jboss-resteasy application and rerun the client to produce the same output.