Hi Team,

I want to create a simple XMl file with few fields...
Below is my code for the same

global class cls_OppFilessent{
     public static string OppFilesend(ID Optid)
     {
       Opportunity rew=new Opportunity();
        rew =[SELECT id,Name,Booking_Date__c,Type,Trade_In__c,VW_Delivery_Date__c FROM Opportunity where id='0067F00000E9VxaQAF'];
      Dom.Document doc = new Dom.Document();
      XmlStreamWriter w = new XmlStreamWriter();
      w.writeStartDocument(null, '1.0');
      w.writeStartElement(null, 'Opportunities', null); //this will be ROOT of <Opportunities> in XML

              
              w.writeStartElement(null, 'Opportunity', null);//Element <Opportunity>
          
              w.writeStartElement(null, 'Id', null);//Element </Id>
              w.writeCharacters(rew.Id);
              w.writeEndElement();//Element </Id>
      
              //Element <BookingDate>
              w.writeStartElement(null, 'BookingDate', null);
              //w.writeEndElement();
              if(rew.Booking_Date__c!=null)
              {
                  //w.writeStartElement(null, 'BookingDate', null);
                  w.writeCharacters(String.valueOf(rew.Booking_Date__c)); 
                     
              }
              w.writeEndElement();
              
              
              w.writeStartElement(null, 'Name', null);
              if(rew.Name!=null)
              {
                  w.writeCharacters(rew.Name);
                  
              }
                  w.writeEndElement();
                  
              
              
              //Element <TradeIN>
              w.writeStartElement(null, 'TradeIN', null);
              if(rew.Trade_In__c!=null)
              {
                  w.writeCharacters(String.valueOf(rew.Trade_In__c));
                  
              }
                  w.writeEndElement();
                  
                  
             w.writeStartElement(null, 'Type', null);
              if(rew.Type!=null)
              {
                  w.writeCharacters(rew.Type);
              }
                  w.writeEndElement();
              
              //Element <DeliveryDate>
              w.writeStartElement(null, 'DeliveryDate', null);
              if(rew.VW_Delivery_Date__c!=null)
              {
                  w.writeCharacters(String.valueOf(rew.VW_Delivery_Date__c)); 
              }
                  w.writeEndElement();
      
      
                w.writeEndDocument();//this will be ROOT CLOSE of </Opportunities> in XML
         string xmlOutput = w.getXmlString();
         system.debug('XML is xmlOutput  '+xmlOutput );
         w.close();
         doc.Load(xmlOutput);
         string xmldata = doc.toXmlString();
         system.debug('XML is '+xmldata);
   
   
    /*
     Blob  csvBlob;
     try{
                csvBlob  = Blob.valueOf(xmldata);  
            }catch(exception e){

                csvBlob  = Blob.valueOf('Some Text');
           }
     
        if(rew.Active__c==true){
            return 'Reward feed already sent';
        }else{
             Attachment attachment = new Attachment();
                attachment.Body = csvBlob ;
                attachment.Name = 'Rewardfile.xml';
                attachment.ParentId = rew.id;
             insert attachment;
          
           rew.Active__c=true;
           Update rew; 
          return 'XML: '+xmldata;
         }*/
         
         return 'XML: '+xmldata; // Pranav - temporary return - remove this once BLOB code is tested
    
   }
}


Test Class:

@isTest
public class test_OppFilessent{
    public static testMethod void m1(){
      
         /*Time_Based_Mgmnt__c t = new Time_Based_Mgmnt__c ();
         t.Name='Q1';
            t.Start_Date__c=Date.Valueof('2014-01-01');
            t.End_Date__c=Date.Valueof('2014-03-01');
        insert t;
      
      
        Reward__c rwrd= new Reward__c();
         //   rwrd.Name='test';
            rwrd.Rward_Amount__c=5000;
            rwrd.Active__c =true;
            rwrd.User__c = userinfo.getUserId();
            rwrd.Time_Based_Mgmnt__c = t.id;
          insert rwrd; 
       */
        //cls_RewardFeedSent.rewardfeedsend('0067F00000E9VxaQAF');
       
       
        //rwrd.Active__c =false;
        //update rwrd;
        ID sfdcOptyID = '0067F00000E9VxaQAF';
        cls_OppFilessent.OppFilesend(sfdcOptyID);
       
    }
}

But i am getting error as

System.QueryException: List has no rows for assignment to SObject


Class.cls_OppFilessent.OppFilesend: line 5, column 1
Class.test_OppFilessent.m1: line 26, column 1


please help