Convert HashMap to string comma separated

Question

I have a class ShoppingCartHelper and a method.

private static Map<Product, ShoppingCartEntry> cartMap = new HashMap<Product, ShoppingCartEntry>();

And method that stores data product to cartMap:

public static List<Product> getCartList() {
    List<Product> cartList = new Vector<Product>(cartMap.keySet().size());
    for(Product p : cartMap.keySet()) {
        cartList.add(p);
    }
    return cartList;
}

In other class I call stored data on map:

private List<Product> mCartList;
mCartList = ShoppingCartHelper.getCartList();

and print it in comma separated:

StringBuilder commaSepValueBuilder = new StringBuilder();
for ( int i = 0; i< mCartList.size(); i++) {
   commaSepValueBuilder.append(mCartList.get(i));
   if ( i != mCartList.size()-1) {
       commaSepValueBuilder.append(", ");
   }
}
System.out.println(commaSepValueBuilder.toString());

Its printed like com.android.test@34566f3,com.android.test@29f9042

How do I print data on Map to string (human readable)?

Answer 1

Make your Product class overriding the toString() method or in your custom logic, make a string builder appending not the element itself, but it's fileds, which you wish to recieve as text description of the product instance. I mean something like this:

//since I don't know, what is the Product class, I supposed it has a name filed
commaSepValueBuilder.append(mCartList.get(i).getName());