REST Service Calls for Java - 1.0

Extension ID

com.castsoftware.java.service

What’s new?

See REST service call for Java - 1.0 - Release Notes for more information.

Description

This extension provides support for some web services calls from Java.

Supported REST client libraries

Native	java.net.URLConnection java.net.HttpURLConnection
JAX-RS	javax.ws.rs.client.ClientBuilder javax.ws.rs.client.Client org.glassfish.jersey.client.JerseyClient javax.ws.rs.client.WebTarget javax.ws.rs.client.Invocation javax.ws.rs.client.Invocation.Builder javax.ws.rs.core.UriBuilder org.jboss.resteasy.client.jaxrs.ResteasyClient org.jboss.resteasy.client.jaxrs.ResteasyWebTarget org.jboss.resteasy.client.ClientRequest com.sun.jersey.api.client.Client com.sun.jersey.api.client.WebResource
Spring	org.springframework.web.client.RestTemplate org.springframework.web.util.UriComponentsBuilder org.springframework.web.util.UriComponents org.springframework.web.util.HtmlUtils org.springframework.social.support.URIBuilder org.springframework.web.reactive.function.client.WebClient
Apache	org.apache.cxf.jaxrs.client.WebClient org.apache.http.client.HttpClient org.apache.http.impl.client.CloseableHttpClient org.apache.http.impl.nio.client.CloseableHttpAsyncClient org.apache.http.client.utils.URIBuilder org.apache.wink.client.Resource org.apache.wink.client.RestClient
Vert.x	io.vertx.core.http.HttpClientRequest io.vertx.ext.web.client.HttpRequest io.vertx.ext.web.client.WebClient
okhttp	com.squareup.okhttp.OkHttpClient okhttp3.OkHttpClient
Other	org.resthub.web.Client org.springframework.cloud.openfeign.FeignClient org.springframework.cloud.netflix.feign.FeignClient feign.Feign feign.RequestLine retrofit2.http.DELETE retrofit2.http.GET retrofit2.http.PATCH retrofit2.http.POST retrofit2.http.PUT

Function Point, Quality and Sizing support

This extension provides the following support:

Function Points (transactions): A green tick indicates that OMG Function Point counting and Transaction Risk Index are supported
Quality and Sizing: A green tick indicates that CAST can measure size and that a minimum set of Quality Rules exist

Function Points (transactions)	Quality and Sizing

AIP Core compatibility

This extension is compatible with:

AIP Core release	Supported
8.3.x

Dependencies with other extensions

The REST Service Calls for Java extension requires that ≥ 1.2.8-funcrel of the JEE Analyzer is also installed and used in order to ensure the most complete set of results. This dependency with the JEE Analyzer is not automatically handled when downloading the REST Service Calls for Java extension via CAST Extension Downloader, CAST Server Manager or AIP Console, therefore you must MANUALLY download and install the JEE Analyzer before starting an analysis.

What results can you expect?

Features

This extension analyzes web service calls made from Java code through classic fluent APIs. For example with com.sun.jersey:

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;


class Main
{
    public static void main(String[] args) {
        Client client = Client.create();

        WebResource webResource = client
                .resource("http://localhost:8080/RESTfulExample/rest/json/metallica/get");

        ClientResponse response = webResource.accept("application/json")
                .get(ClientResponse.class);

    }

}

Client side load balancing

Usage of org.springframework.cloud.client.loadbalancer.LoadBalancerClient allows to choose a service to call so impacts the URL called:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.client.RestTemplate;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.cloud.client.ServiceInstance;
import java.net.URI;

class Main
{
    @Autowired
    private LoadBalancerClient loadBalancerClient;

    void f()
    {
        RestTemplate client ;
        ServiceInstance serviceInstance = loadBalancerClient.choose("user-auth");
        String path = serviceInstance.getUri().toString() + "/oauth/token";
        client.put(path, client);
    }
}

Feign

Feign is a declarative web service client which makes writing web service clients easier. Native sample: “RequestLine” annotation indicates the presence of feign web service:

interface GitHub {
  @RequestLine("GET /repos/{owner}/{repo}/contributors")
  List<Contributor> contributors(@Param("owner") String owner, @Param("repo") String repo);
}
 
public static class Contributor {
  String login;
  int contributions;
}
 
public class MyApp {
  public static void main(String... args) {
    GitHub github = Feign.builder()
                         .decoder(new GsonDecoder())
                         .target(GitHub.class, "https://api.github.com");
   
    // Fetch and print a list of the contributors to this library.
    List<Contributor> contributors = github.contributors("OpenFeign", "feign");
    for (Contributor contributor : contributors) {
      System.out.println(contributor.login + " (" + contributor.contributions + ")");
    }
  }
}

“FeignClient” annotation associated with “RequestMapping” and “GetMapping” annotations indicates the presence of feign web service:

import java.util.List;
 
@FeignClient(
        name = "${client.name}",
        path= "${client.path}",
        configuration = FeignConfiguration.class
)
public interface ClientConfiguration {
 
    @RequestMapping(method = RequestMethod.POST, value = "/services/clients")
    List<SupplierTransitionDTO> getData(@RequestBody List<String> codes) throws FeignException;
}

@FeignClient(name = "Client", url = "${build.api.url}", path = "/api/v1")
public interface ClientConfiguration {

    @GetMapping("/sites/{site-id}/clients")
    ConsentResponse getConfiguration(
            @PathVariable("site-id") String siteId,
            @RequestParam("types") List<ConfigType> types);
}

Retrofit2.http

With Retrofit 2, endpoints are defined inside an interface using special retrofit annotations to encode details about the parameters and request method. Annotations like “GET”, “POST”, “PUT”, “DELETE” and “PATCH”, for example:

import retrofit2.http.GET;

public interface ExampleGetService {
    @GET("getservice.example")
    Single<ExampleApi> getMode();
}

Objects

The following objects are displayed in CAST Enlighten:

Icon	Description
	Delete Resource Service
	Get Resource Service
	Post Resource Service
	Put Resource Service
	Patch Resource Service

Rules

None.

Limitations

When the code uses a custom URL builder, we cannot evaluate the URL.
When the standard java API is encapsulated in a custom method where the “http method” (put, get, post, delete) is passed as a parameter, the dynamic evaluation will generally fail.

class MyHttpCall
{
   void execute(String url, String method)
   {
      Client client = ClientBuilder.newClient();
      WebTarget myResource = client.target(url);

      if (method == "GET")
      {
          String response = myResource.request(MediaType.TEXT_PLAIN).get(String.class);
      }
      else if (method == "PUT")
      {
          myResource.request(MediaType.TEXT_PLAIN).put(null);
      }
         
   }

}

Manual creation of feign clients is not supported