webservice calling from url

[Miku Ranjan]

Hi,
I want to call web service direcltly using a url is it possible?
If yes how.

Thanks
Miku

[William Brogden]

Of course it is possible, how depends on the service so you will need documentation of the service.

1. if a SOAP service you will need to create a SOAP message as a request to the URL.
2. if a REST service you will need a URL that is correctly formatted to address the service HTTP method desired

Bill

[H Paul]

I'll give you what I have - no more no less

Assume, you use window

1. Go to http://maven.apache.org/download.html

Download maven

2. Go to http://www.jboss.org/resteasy
Download resteasy-jaxrs-2.2.3.GA-all.zip
Unzip it to C:\ drive for example.

Go to
resteasy-jaxrs-2.2.3.GA\examples
examples\oreilly-workbook\oreilly-workbook
examples\oreilly-workbook\ex03_1
read README.txt

Basic: resteasy-jaxrs-2.2.3.GA is an implementation of JAX-RS - Restful web service.

ex03_1 has a client using URL. So here you have an example of using URL to talk to Restful web service on the server side.

Run the example;

C:\\resteasy-jaxrs-2.2.3.GA\examples\oreilly-workbook\ex03_1>mvn install
you will the output on the command line

For more: Use your friend GOOGLE for key words like:

Restful web service with URL
Soapful web service with URL
Soapful JAX-WS web service
Restful JAX-RS web service

[H Paul]

For Restful web service, below are 2 different CLIENT ways:

1. Use Jersey JAX-RS client API
2. Use Apache HttpClient 4.x

If you scan the code, you will see that I'm NOT the President.

=== SERVER side:

package test.rest;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Response;

@Path("/president")
public class PresidentResource {
	private static Map<Integer, President> presidents;
	
	static { 
		presidents=new HashMap<Integer, President>();
		President jfk = new President(1, "John", "Kennedy");
		presidents.put(jfk.getId(), jfk);
		President fm = new President(2, "Francois", "Mitterrand");
		presidents.put(fm.getId(), fm);		
		President nm = new President(3, "Nelson", "Mandela");
		presidents.put(nm.getId(), nm);	
	}
	
	@GET
	@Path("{id}")
	@Produces("application/xml")
	public President getPresident(@PathParam("id")int id) {
		if (presidents.get(id)==null)
			throw new WebApplicationException(Response.Status.NOT_FOUND);
		return presidents.get(id);
	}
}


==== CLIENT side

package test.rest;

import java.io.StringReader;

import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathFactory;

import org.junit.Assert;
import org.xml.sax.InputSource;

public class PresidentResourceTest {
	protected void testIt(String xmlPresident) throws Exception {
		//Test the expected with the actual returned from the server 		
		XPathFactory factory = XPathFactory.newInstance();
		XPath xpath= factory.newXPath();		
        XPathExpression xPathExpression = xpath.compile("/President/LastName");   
        Object lastname = xPathExpression.evaluate(new InputSource(new StringReader(xmlPresident)));
		Assert.assertEquals("Kennedy", lastname);
	}
}

package test.rest;

import javax.ws.rs.core.MediaType;

import org.junit.Test;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;
import com.sun.jersey.api.client.config.ClientConfig;
import com.sun.jersey.api.client.config.DefaultClientConfig;

public class PresidentResourceJerseyTest extends PresidentResourceTest{
	@Test
	public void getPresidentTest() throws Exception{
		ClientConfig config = new DefaultClientConfig();
		Client client = Client.create(config);
		
		WebResource service = client.resource("http://localhost:28080/JerseyJAX-RS/");
		ClientResponse response= service.path("rest").path("president").path("/1")
					.accept(MediaType.APPLICATION_XML_TYPE).get(ClientResponse.class);
		
		String xmlPresident=response.getEntity(String.class);
		super.testIt(xmlPresident);
		
	}
}


package test.rest;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.junit.Test;

public class PresidentResourceHttpClientTest extends PresidentResourceTest{
	
	@Test
	public void getPresidentTest() throws Exception {
		HttpClient httpclient= new DefaultHttpClient();
		HttpGet httpget = new HttpGet("http://localhost:28080/JerseyJAX-RS/rest/president/1");
		HttpResponse httpResponse = httpclient.execute(httpget);
		if (httpResponse!=null && httpResponse.getStatusLine().getStatusCode()==200){			
			String xmlPresident=EntityUtils.toString(httpResponse.getEntity());
			super.testIt(xmlPresident);
		}
	}
}

[Miku Ranjan]

Hi Paul,
Thanks for the reference and the example code.
It is really helpful.

[H Paul]

For Server side, I re-write my Rest President to Soap President

For Client side, I use Apache-HttpClient/4.1.2 to send a Soap Request to the Server. The Soap Request is hard-coded.

Normally, for fun, we do this way because we should use JAX-WS or SAAJ by constraint.

Server side:

package test.soap;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;

import javax.jws.WebService;

@WebService
public class PresidentService {
	private static Map<Integer, President> presidents;
	private static AtomicInteger IDS = new AtomicInteger(1);
	
	static {
		presidents=new HashMap<Integer, President>();
		President jfk = new President(IDS.getAndIncrement(), "John", "Kennedy");
		presidents.put(jfk.getId(), jfk);
		President fm = new President(IDS.getAndIncrement(), "Francois", "Mitterrand");
		presidents.put(fm.getId(), fm);		
		President nm = new President(IDS.getAndIncrement(), "Nelson", "Mandela");
		presidents.put(nm.getId(), nm);	
	}

	public President getPresident(int id) throws PresidentException {
		if (presidents.get(id)==null)
			throw new PresidentException("Unknown President Id");
		return presidents.get(id);
	}
}


Client side:

package test.soap;

import junit.framework.Assert;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.junit.Test;

import test.rest.PresidentResourceTest;

public class PresidentServiceTest extends PresidentResourceTest {
	@Test
	public void getPresidentTest() throws Exception {
		HttpClient httpclient= new DefaultHttpClient();
		HttpPost httpPost=new HttpPost("http://localhost:28080/JerseyJAX-WS/President");	
		
		String requestSoapMessage= getRequestSoapMessage();
		StringEntity entity = new StringEntity(requestSoapMessage);
		entity.setContentType("text/xml");
		httpPost.setEntity(entity);
		HttpResponse httpResponse = httpclient.execute(httpPost);
		
		if (httpResponse!=null && httpResponse.getStatusLine().getStatusCode()==200){			
			String xmlPresident=EntityUtils.toString(httpResponse.getEntity());
			super.testIt(xmlPresident);
		} 
		
		Assert.fail("Use SOAPUI: <faultstring>Unknown President Id</faultstring>");
	}

	private String getRequestSoapMessage() { //The Soap Request is hard-coded.
		// TODO Auto-generated method stub
		String requestSoapMessage="<soapenv:Envelope xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:soap=\"http://soap.test/\"><soapenv:Header/><soapenv:Body><soap:getPresident><arg0>1</arg0></soap:getPresident></soapenv:Body></soapenv:Envelope>";
		return requestSoapMessage;
	}
}