How to convert List<object> into List<string>

Question

Here is my apex code"

apex clas

public class GetRestfulExampleSu{

public string jsonStr {get;set;}
public Pagereference getJSONFromREST() {
        Http h = new Http();
        HttpRequest req = new HttpRequest();
        req.setEndpoint('http://dz.co.rplug.renault.com/localsemiclair/BAWn'); 
        req.setHeader('Accept','application/JSON');
        req.setMethod('GET');
        HttpResponse res = h.send(req); 
        jsonStr= res.getBody();

        system.debug('jsonStr>>>>-->>>>>>'+jsonStr);

        jsonStr= res.getBody();

        Map<String,Object> rawObj = (Map<String,Object>) JSON.deserializeUntyped(jsonStr);

   Map<String,Object> responseObj = (Map<String,Object>)rawObj.get('localSemiClair');
   Map<String,Object> responseObjinside2 = (Map<String,Object>)responseObj.get('mapRepresentation'); 
   Map<String,Object> responseObjinside3 = (Map<String,Object>)responseObjinside2 .get('map');   
   List<Object> reqs = (List<Object>) responseObjinside3 .get('map');
   List<string> lsstr= new List<string> ();

   for(Object a:reqs){
     lsstr=(List<string>)a;  
   }


      return null;
 }

}

I want to convert "reqs" value into a list of string. It showing error.Please help me out.Thanks in advance!!

Answer 1

Instead of this code:

List<Object> reqs = (List<Object>) responseObjinside3 .get('map');
List<string> lsstr= new List<string> ();

for(Object a:reqs){
   lsstr=(List<string>)a;  
}

Use this code:

List<Object> reqs = (List<Object>) responseObjinside3.values();
List<string> lsstr= new List<string> ();

for(Object a: reqs){
   lsstr.add(String.valueOf(a));
}

Answer 2

List<Object> myStringObjects = new List<Object>{'a', 'b', 'c'};

List<String> myStrings = String.join(myStringObjects, ';').split(';');

We can go future and create method:

public List<String> convert(Object iterableObject) {
    return String.join(new List<Object>(iterableObject), ';').split(';');
}

List<String> myStringsFromSet = convert(new Set<Object>{'a', 'b', 'c'});

List<String> myStringsFromList = convert(new List<Object>{'a', 'b', 'c'});

Pros:

• Code is very simple

Cons:

• Be careful with the separator (in my example ;), because if your strings contain it, it will be working not as expected.