public class ExternalCall
{
    //Static global attribute from external system callouts
    @TestVisible private static final String username;
    @TestVisible private static final String password;
    @TestVisible private static final String endpoint;
    // Initialize all attributes using custom settings.
    // Static is to initialize at the time of class load.
    static
    {
        username=Credentials__c.getInstance('username').Value__c;
        password=Credentials__c.getInstance('password').Value__c;
        endpoint=Credentials__c.getInstance('endpoint').Value__c;
    }
        
   
    @future(callout=true)
    public static void updateStatus()
    {
        Http http = new Http();
        // soapbody string creation to make https callout using SOAP xml.
        String soapBody;
        HttpRequest req = new HttpRequest();
        HttpResponse res = new HttpResponse();
        try
        {
            req=getRequest();
            soapBody=getHeader();
            soapBody+='<soapenv:Body>';
            soapBody+='<ns7:Update xmlns:ns7="urn:messages.ws.rightnow.com/v1_2">';
            soapBody+='<ns7:RNObjects  xsi:type="ns2:GenericObject" xmlns:ns2="urn:generic.ws.rightnow.com/v1_2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">';
            soapBody+='<ID id="" xmlns="urn:base.ws.rightnow.com/v1_2"/>';
            soapBody+='<ns2:ObjectType>';
            soapBody+='<ns2:Namespace xsi:nil="1"/>';
            soapBody+='<ns2:TypeName>Incident</ns2:TypeName>';
            soapBody+='</ns2:ObjectType>';
            soapBody+='<ns2:GenericFields dataType="OBJECT" name="StatusWithType">';
            soapBody+='<ns2:DataValue>';
            soapBody+='<ns2:ObjectValue xsi:type="ns2:GenericObject">';
            soapBody+='<ns2:ObjectType>';
            soapBody+='<ns2:TypeName>StatusWithType</ns2:TypeName>';
            soapBody+='</ns2:ObjectType>';
            soapBody+='<ns2:GenericFields dataType="NAMED_ID" name="Status">';
            soapBody+='<ns2:DataValue>';
            soapBody+='<ns2:NamedIDValue>';
            soapBody+='<Name xmlns="urn:base.ws.rightnow.com/v1_2">Complete</Name>';
            soapBody+='</ns2:NamedIDValue>';
            soapBody+='</ns2:DataValue>';
            soapBody+='</ns2:GenericFields>';
            soapBody+='</ns2:ObjectValue>';
            soapBody+='</ns2:DataValue>';            
            soapBody+='</ns2:GenericFields>';         
            soapBody+='</ns7:RNObjects>';
            soapBody+='<ns7:ProcessingOptions>';
            soapBody+='<ns7:SuppressExternalEvents>false</ns7:SuppressExternalEvents>';
            soapBody+='<ns7:SuppressRules>false</ns7:SuppressRules>';
            soapBody+='</ns7:ProcessingOptions>';
            soapBody+='</ns7:Update>';
            soapBody+='</soapenv:Body>';
            soapBody+='</soapenv:Envelope>'; 
            req.setHeader('Content-Length',String.valueOf(soapBody.length()));
            system.debug('Message'+soapBody);
            req.setTimeout(120000);
            req.setBody(soapBody);
            res=http.send(req); 
            system.debug(res);
            // If response is 200 then it success
        }
        catch(Exception e)
        {
             system.debug(e);           
        }
         
    }   
     @TestVisible
    private static HttpRequest getRequest()
    {       
            HttpRequest req = new HttpRequest();
            req.setMethod('POST');
            req.setHeader('Content-Type','text/xml');
            req.setHeader('SOAPAction', endpoint);
            req.setHeader('Authorization', 'Basic Og==');        
            req.setEndpoint(endpoint);  
            return req;
    }
 }