How to call web service from java code example (How to generate proxy java class)

How to call web service from java code from standalone application, from Java Bean or from Servlet.

We have two ways:

• For Java Bean or Servlet we use Eclipse (NWDS) to generate Java Class Client - Proxy Class.
• For standalone (desktop) we use SAAJ - SOAP with Attachments API for Java.

Generate web-service client (Proxy Class) in Eclipse:

1. Create EJB Module project in Eclipse (NWDS)
2. Create Enterprise Application project in Eclipse (NWDS)
3. Import here web-service WSDL
4. Right click on WSDL -> Web Services -> Generate Client
5. In pop-up window move slider to "Develop client" level. Check that "client project" and "EAR project" is yours. Go to next and then push finish.
6. Eclipse has created package which contains your Proxy Class for your web-service. It's name looks like "<NameOfYourWebService> + Service" - remember that class.
7. If you want to call web-service from Java Bean go to 8 step, if from servlet go to 9 step. 
8. Create Session Java Bean. In your Java Bean create parameter "webService" with type of your proxy class ( it's name "<NameOfYourWebService> + Service" - remember? ). Over that parameter specify "@WebServiceRef" annotation and set: "name=<NameOfYourWebService> + Service".
9. Create Servlet. In your Servlet create parameter "webService" with type of your proxy class ( it's name "<NameOfYourWebService> + Service" - remember? ). Over that parameter specify "@WebServiceRef" annotation and set "name=<NameOfYourWebService> + Service".
10. Now if you want call web-service from Servlet, J2EE engine will initialize our parameter "webService" with proxy class when it will be initialized. If you want call web-service from another Java Bean, you can use JNDI to get initialized proxy class. Do that like this: javax.naming.InitialContext.doLookup("<Java Bean JNDI Name of your Java Bean>");
11. In Java Bean or Servlet create method where you want to call web-service.
12. In parameter "webService" you have method "get + <NameOfYourWebService> + Port". Call that and you will get your web-service object. This object contains all operations of your web-service. Use it!

Call web-service from standalone application (desktop) using SAAJ:

We will create SOAP message, using SAAJ, and then we will call web service.

1. Create SOAP message:

If you have web service operation getName and this operation has input structure like this:

<user>
  <userId>1</userId>
</user>

Then we will create SOAPMessage like this:

MessageFactory mf = MessageFactory.newInstance();
SOAPMessage msg = mf.createMessage();

SOAPPart soapPart = msg.getSOAPPart();
SOAPEnvelope envelope = soapPart.getEnvelope();
SOAPBody body = envelope.getBody();

//create structure like our web service operation input
SOAPElement bodyElement = body.addBodyElement(envelope.createName(
"<web service operation name - getName>", "<prefix, I use 'ns1'>", "<uri, it is property 'targetNamespace' in annotation '@WebService' in your web service java class>"));
SOAPElement nodeUser = bodyElement.addChild("user");
SOAPElement nextNode = nodeUser.addChildElement("userId").addTextNode("1");

//if you should make authorization do this
MimeHeaders headers = msg.getMimeHeaders();
String upas = "login" + ":" + "password";
String auth = "Basic " + new String(javax.xml.bind.DatatypeConverter.printBase64Binary(upas.getBytes()));
headers.addHeaders("Authorization", new String(auth.getBytes()));

2. Now we can call web service with our SOAPMessage

URL url = new URL("<url to web service wsdl without '?wsdl', or url in web service wsdl in node 'address' in property 'location'>");

SOAPConnectionFactory cf = SOAPConnectionFactory.newInstance();
SOAPConnection conn = cf.createConnection();
//here we call web service by java code
SOAPMessage replay = conn.call(msg, url);// replay contains web service response
conn.close();