java.lang.ClassCastException: java.lang.Double cannot be cast to java.lang.String

Question

I have done with code in Android:

List<String> spinnerArray =  new ArrayList<String>();
for (int i = 0; i < items.size(); i++) {
    LinkedTreeMap<String, String> item = (LinkedTreeMap) items.get(i);

    // THIS LINE THROW EXCEPTION
    double d = Double.parseDouble(item.get("id").toString());

    locations.put(Integer.parseInt(item.get("id")), item.get("name"));
    spinnerArray.add(item.get("name"));
}

I get the error when I define the "d" variable.
The strange thing is if I run the same line in the debug I get the double value I need.

UPDATE ANSWER

On the debug window I have:

items.get(i) = {LinkedTreeMap@5317} size = 5
0 = {LinkedTreeMap$Node@5378} "id" -> "1.0"
    key = "id"
    value = {Double@5384} "1.0"

Answer 1

Seems that LinkedTreeMap items is of type [String, Object] and not [String, String].

So your code should look like:

LinkedTreeMap<String, Object> item = (LinkedTreeMap) items.get(i);

Thanks to Timothy Truckle.

Answer 2

The long term solution to your problem is to define a custom class to be used as Data Transfer Object (DTO) where you cann access an items properties in a typesafe way:

class Item {
   private double id;
   private String name;
   public void setId(double id){this.id=id;}
   public double getId(){ return id;}
   public void setName(String name){this.name = name;}
   public String getName(){return name;}
}

usage:

for (int i = 0; i < items.size(); i++) {
    Item item = (LinkedTreeMap) items.get(i);

    // THIS LINE THROW EXCEPTION
    double d = item.getId();

    locations.put((int)item.getId(), item.getName());