Call Web Services from external sources

A.

To call web services from external sources in Apex and Visualforce Controllers, you can use SOAP Web Service Callouts.

SOAP stands for Simple Object Access Protocol, and it is a protocol used to exchange structured data between applications over the internet. SOAP is commonly used to implement web services, which are application components that can be accessed by other applications over the internet.

To call a SOAP web service from Apex, you need to use the HttpRequest and HttpResponse classes to make an HTTP request to the web service endpoint. You also need to use the WebServiceCallout.invoke() method to execute the SOAP request and get the response.

Here is an example of how to call a SOAP web service from Apex:

phpCopy code
HttpRequest req = new HttpRequest(); req.setEndpoint('https://www.example.com/webservice'); req.setMethod('POST'); req.setHeader('Content-Type', 'text/xml'); req.setBody('<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:example="http://www.example.com/"><soapenv:Header/><soapenv:Body><example:GetData><example:Input>test</example:Input></example:GetData></soapenv:Body></soapenv:Envelope>');  Http http = new Http(); HttpResponse res = http.send(req);  System.debug(res.getBody()); 

In this example, we create an HttpRequest object and set its properties to specify the web service endpoint URL, HTTP method, request headers, and SOAP request body. We then create an Http object and use its send() method to execute the HTTP request and get the HTTP response. Finally, we use the getBody() method of the HttpResponse object to get the SOAP response body and log it to the debug log.

In summary, you can call web services from external sources in Apex and Visualforce Controllers by using SOAP Web Service Callouts.