In this article, lets discuss about accessing a Web Service using SAAJ.
What is SAAJ?
SOAP with Attachments API for Java (SAAJ) is mainly used for dealing directly with SOAP Request/Response messages which happens behind the scenes in any Web Service API. It allows the developers to directly send and receive soap messages instead of using JAX-WS.
Let's see an example of how to access the Web Service created in the Axis2 - Simple Web Service Example.
Now, we are going to develop Web Service Client using SAAJ API. Have a look at the following Web Service Client code.
SaaJSoapClient.java
import javax.xml.soap.SOAPBody;
import javax.xml.soap.SOAPConnection;
import javax.xml.soap.SOAPConnectionFactory;
import javax.xml.soap.SOAPElement;
import javax.xml.soap.SOAPEnvelope;
import javax.xml.soap.SOAPMessage;
import javax.xml.soap.SOAPPart;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
/**
* SOAP Client Implementation using SAAJ Api.
*/
public class SaaJSoapClient
{
/**
* Method used to create the SOAP Request
*/
private static SOAPMessage createSOAPRequest() throws Exception
{
MessageFactory messageFactory = MessageFactory.newInstance();
SOAPMessage soapMessage = messageFactory.createMessage();
SOAPPart soapPart = soapMessage.getSOAPPart();
/*
Construct SOAP Request Message:
<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope"
xmlns:sam="http://samples.axis2.techdive.in">
<soap:Header/>
<soap:Body>
<sam:getStudentName>
<!--Optional:-->
<sam:rollNumber>3</sam:rollNumber>
</sam:getStudentName>
</soap:Body>
</soap:Envelope>
*/
// SOAP Envelope
SOAPEnvelope envelope = soapPart.getEnvelope();
envelope.addNamespaceDeclaration("sam", "http://samples.axis2.techdive.in");
// SOAP Body
SOAPBody soapBody = envelope.getBody();
SOAPElement soapBodyElem = soapBody.addChildElement("getStudentName", "sam");
SOAPElement soapBodyElem1 = soapBodyElem.addChildElement("rollNumber", "sam");
soapBodyElem1.addTextNode("3");
soapMessage.saveChanges();
// Check the input
System.out.println("Request SOAP Message = ");
soapMessage.writeTo(System.out);
System.out.println();
return soapMessage;
}
/**
* Method used to print the SOAP Response
*/
private static void printSOAPResponse(SOAPMessage soapResponse) throws Exception
{
TransformerFactory transformerFactory = TransformerFactory.newInstance();
Transformer transformer = transformerFactory.newTransformer();
Source sourceContent = soapResponse.getSOAPPart().getContent();
System.out.println("\nResponse SOAP Message = ");
StreamResult result = new StreamResult(System.out);
transformer.transform(sourceContent, result);
}
/**
* Starting point for the SAAJ - SOAP Client Testing
*/
public static void main(String args[])
{
try
{
// Create SOAP Connection
SOAPConnectionFactory soapConnectionFactory = SOAPConnectionFactory.newInstance();
SOAPConnection soapConnection = soapConnectionFactory.createConnection();
//Send SOAP Message to SOAP Server
String url = "http://localhost:8080/axis2/services/Student?wsdl";
SOAPMessage soapResponse = soapConnection.call(createSOAPRequest(), url);
// Process the SOAP Response
printSOAPResponse(soapResponse);
soapConnection.close();
}
catch (Exception e)
{
System.err.println("Error occurred while sending SOAP Request to Server");
e.printStackTrace();
}
}
}
Here we create a SOAP request for accessing the Student details. Look in to the createSOAPRequest() method. It creates a SOAP request message envelope, which includes name space, web service method name and necessary parameters for the same.
This method returns a Soap Message, which is sent as a request to Web Service. The SOAP response received is printed using the printSOAPResponse(..) method.
Output
Here is the sample output:
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:sam="http://samples.axis2.techdive.in"><SOAP-ENV:Header/><SOAP-ENV:Body><sam:getStudentName><sam:rollNumber>3</sam:rollNumber></sam:getStudentName></SOAP-ENV:Body></SOAP-ENV:Envelope>
Response SOAP Message =
<?xml version="1.0" encoding="UTF-8"?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><ns1:getStudentNameResponse xmlns:ns1="http://samples.axis2.techdive.in"><ns1:return>Jack</ns1:return></ns1:getStudentNameResponse></soapenv:Body></soapenv:Envelope>