How to fix this "incompatible types" issue

[aneuryzma]

In the code below if I don't use a cast:

ArrayList<Instance> currentEvent = mapItem.getValue();

I get:

 incompatible types
found   : java.lang.Object
required: java.util.ArrayList<Instance>
				ArrayList<Instance> currentEvent = mapItem.getValue();

If I use a cast:

ArrayList<Instance> currentEvent = (ArrayList<Instance>) mapItem.getValue();

I get

warning: [unchecked] unchecked cast
found   : java.lang.Object
required: java.util.ArrayList<Instance>
				ArrayList<Instance> currentEvent = (ArrayList<Instance>) mapItem.getValue();

mapItem is aMap.Entry. What am I doing wrong ?
thanks

[ozzyman]

you may add items to an arraylist like this:

currentEvent.add(Object)

but the object should match the ArrayList type in this case: Instance


but the point is currentEvent = Object is wrong syntax.

[Fubarable]

Are all your Sets, Maps, etc generic?

[aneuryzma]

@ozzyman But i don't need to add an item to an ArrayList, I'm getting an ArrayList and that's it.

@Fubarable These are the initializations

instancesLists = new HashMap<String, ArrayList<Instance>>();
...
Iterator it = instancesLists.entrySet().iterator();
	while (it.hasNext()) {
		Map.Entry mapItem = (Map.Entry)it.next();

thanks

[aneuryzma]

Any help ? I'm a bit stuck

I'm currentEvent is a List i'm retrieving from the mapItem, I'm not adding items to currentEvent.

mapItem contains Lists

[JosAH]

Any help ? I'm a bit stuck

I'm currentEvent is a List i'm retrieving from the mapItem, I'm not adding items to currentEvent.

mapItem contains Lists

Your Iterator is a 'raw' iterator; it should be an:

Iterator<Map.Entry<String, ArrayList<Instance>>>

object instead. Raw iterators just return Objects; you don't want that.

kind regards,

Jos

[aneuryzma]

I've changed as you suggest, the iterator declaration

Iterator<Map.Entry<String, ArrayList<Instance>>> it = instancesLists.entrySet().iterator();

but I still get the same error

incompatible types
found   : java.lang.Object
required: java.util.ArrayList<Instance>
				ArrayList<Instance> currentEvent = mapItem.getValue();

This is my code: #1722600 - Pastie

[JosAH]

I've changed as you suggest, the iterator declaration

Iterator<Map.Entry<String, ArrayList<Instance>>> it = instancesLists.entrySet().iterator();

but I still get the same error

incompatible types
found   : java.lang.Object
required: java.util.ArrayList<Instance>
				ArrayList<Instance> currentEvent = mapItem.getValue();

This is my code: #1722600 - Pastie

Then you're using a raw Map.Entry type which implies that you're using a raw Map somewhere.

kind regards,

Jos

[aneuryzma]

all right, solved, thanks