Checking an object in Arraylist against empty string

Question

Hi all,
Im storing a collection of objects in Arraylist.Among them , one of the objects has an empty string.How can i check whether an object contains empty string.I tried to check using the follwing snippet:
ArrayList idList=new ArrayList();
if((idList.get(0)) == null || idList.get(0) == "")
        Debug.log("*****ARRAY LIST IS BLANK 1********");Please help

Answer 1

Here is a bit more deeper code:
HashMap lookupMap= null;
try {
          Object obj = util.lookUp(pid,attributeId,params); // The lookUp method returns an object.
             Debug.log(11, " obj type: " + obj.getClass().getName());
        lookupMap = (HashMap) obj;
Collection mapkeys = lookupMap.keySet();
Iterator itKeySet = mapkeys.iterator();
ArrayList idList = new ArrayList();
ArrayList descList = new ArrayList();
ArrayList lookupKeys = new ArrayList();
while(itKeySet.hasNext())
        lookupKeys.add(itKeySet.next());
for(int i=0; i<lookupKeys.size(); i++)
        String key = (String)lookupKeys.get(i);
    if(key != null && key.startsWith("1_"))
          idList =(ArrayList)lookupMap.get(lookupKeys.get(i));
        if(key != null && key.startsWith("2_"))
          descList=(ArrayList)lookupMap.get(lookupKeys.get(i));
        if(key != null && key.startsWith("1_") && (size == 1))
           descList=(ArrayList)lookupMap.get(lookupKeys.get(i));
ArrayList id1=new ArrayList();
int x=0;
      do
     if(!(idList.get(x)).equals(null) || !(idList.get(x)).equals(""))
                id1.add(idList.get(x));
                Debug.log("*****idList.get(x)********"+idList.get(x));
                Debug.log("*****added to idlist.get(0)********");
                break;
              else
                x++;
     }while(id1.size() == 0);