Access an external web service using SOAP

This sample shows how to make a SOAP request to an external service.

It is based on a working example, but it has been simplified so it is (somewhat) easier to follow. It therefore will not work "as is". Use it as a template to guide your own developments.

Here is the sample WSDL (Web Service Description Language) the code is based on:

<syntaxhighlight lang="xml" enclose="div">

<definitions xmlns="http://schemas.xmlsoap.org/wsdl/"

 xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" 
 xmlns:http="http://schemas.xmlsoap.org/wsdl/http/" 
 xmlns:xs="http://www.w3.org/2001/XMLSchema" 
 xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" 
 xmlns:mime="http://schemas.xmlsoap.org/wsdl/mime/" 
 xmlns:y="http://mydomain.com/calculator/" 
 xmlns:ns="http://mydomain.com/calculator/types/" 
 targetNamespace="http://mydomain.com/calculator/">
  <types>
    <xs:schema targetNamespace="http://mydomain.com/calculator/types/" 
      xmlns="http://mydomain.com/calculator/types/" 
      elementFormDefault="unqualified" attributeFormDefault="unqualified">
        <xs:complexType name="CalculatorInput">
           <xs:sequence>
              <xs:element name="x" type="xs:double"/>
              <xs:element name="y" type="xs:double"/>
           </xs:sequence>
        </xs:complexType>
        <xs:complexType name="CalculatorOutput">
           <xs:sequence>
              <xs:element name="result" type="xs:double"/>
           </xs:sequence>
        </xs:complexType>
        <xs:element name="Add" type="CalculatorInput"/>
        <xs:element name="AddResponse" type="CalculatorOutput"/>
     </xs:schema>
  </types>
  <message name="AddMessage">
     <part name="parameters" element="ns:Add"/>
  </message>
  <message name="AddResponseMessage">
     <part name="parameters" element="ns:AddResponse"/>
  </message>
  <portType name="CalculatorInterface">
     <operation name="Add">
        <input message="y:AddMessage"/>
        <output message="y:AddResponseMessage"/>
     </operation>
  </portType>
  <binding name="CalculatorSoapHttpBinding" type="y:CalculatorInterface">
     <soap:binding style="document" 
        transport="http://schemas.xmlsoap.org/soap/http"/>
     <operation name="Add">
        <soap:operation soapAction="http://mydomain.com/calculator/#Add"/>
        <input>
           <soap:body use="literal"/>
        </input>
        <output>
           <soap:body use="literal"/>
        </output>
     </operation>
  </binding>
  <service name="CalculatorService">
     <port name="CalculatorEndpoint" binding="y:CalculatorSoapHttpBinding">
        <soap:address location="http://mydomain.com/Calculator/Calculator.asmx"/>
     </port>
  </service>

</definitions> </syntaxhighlight>

Here is the code that uses that WSDL to access the remote service and connect to it. To use this code, you would place it into a Calculator class, and invoke the add() method from a Rule or from other platform code.

<syntaxhighlight lang="xml" enclose="div">

import com.platform.api.*; import org.json.*; import java.util.Map; import java.util.HashMap; import java.util.Iterator;

public class Calculator {

   //This method makes a request to the external web service
   public void add(Parameters p) throws Exception
   {
     String x = (String)p.get("x");
     String y = (String)p.get("y");
     
     String soapRequest =
       "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"+

"<SOAP-ENV:Envelope xmlns:SOAP-ENV=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:soap=\"http://schemas.xmlsoap.org/wsdl/soap/\" xmlns:http=\"http://schemas.xmlsoap.org/wsdl/http/\" xmlns:xs=\"http://www.w3.org/2001/XMLSchema\" xmlns:soapenc=\"http://schemas.xmlsoap.org/soap/encoding/\" xmlns:mime=\"http://schemas.xmlsoap.org/wsdl/mime/\" xmlns:y=\"http://mydomain.com/calculator/\" xmlns:ns=\"http://mydomain.com/calculator/types/\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\">"+ " <SOAP-ENV:Body>"+ " <mns1:Add xmlns:mns1=\"http://mydomain.com/calculator/\">"+ " <x>" + x + "</x>"+ " <y>" + y + "</y>"+ " </mns1:Add>"+ " </SOAP-ENV:Body>"+ "</SOAP-ENV:Envelope>";

     // Create an HTTP connection to use for the SOAP request
     HttpConnection con = new HttpConnection(
         CONSTANTS.HTTP.METHOD.POST,
         "http://mydomain.com/Calculator/Calculator.asmx");
     
     con.addHeader("SOAPAction","http://mydomain.com/calculator/#Add");      
     con.addHeader("Content-Type","text/xml");
     con.setRequestBody(soapRequest);
     
     // Send the request and get the response
     int code = con.execute();
     String response = con.getResponse();

     /*********************************************
       Sample Response (as determined by the WSDL)

<?xml version=\"1.0\" encoding=\"UTF-8\"?> <SOAP-ENV:Envelope xmlns:SOAP-ENV=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:soap=\"http://schemas.xmlsoap.org/wsdl/soap/\" xmlns:http=\"http://schemas.xmlsoap.org/wsdl/http/\" xmlns:xs=\"http://www.w3.org/2001/XMLSchema\" xmlns:soapenc=\"http://schemas.xmlsoap.org/soap/encoding/\" xmlns:mime=\"http://schemas.xmlsoap.org/wsdl/mime/\" xmlns:y=\"http://mydomain.com/calculator/\" xmlns:ns=\"http://mydomain.com/calculator/types/\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\">"+ <SOAP-ENV:Body>"+ <mns1:AddResponse xmlns:mns1=\"http://mydomain.com/calculator/\"> <result>1</result> </mns1:AddResponse> </SOAP-ENV:Body> </SOAP-ENV:Envelope>

     **********************************************/

     //Extract the result element from the response:
     // - First convert xml response to JSON using org.json package
     // - Then extract the result element
     JSONObject jo = org.json.XML.toJSONObject(response);	      
     String resultElement = jo.getJSONObject("SOAP-ENV:Envelope")

.getJSONObject("SOAP-ENV:Body") .getJSONObject("mns1:AddResponse") .getString("result");

   }

} </syntaxhighlight>