How to fix this "incompatible types" issue

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

Code:

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

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I get:

Code:

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

---

If I use a cast:

Code:

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

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I get

Code:

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

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

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.

Are all your Sets, Maps, etc generic?

@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

Code:

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

---

thanks

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

Quote:

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Originally Posted by 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

---

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

I've changed as you suggest, the iterator declaration

Code:

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

---

but I still get the same error

Code:

---

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

---

This is my code: #1722600 - Pastie

Quote:

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Originally Posted by aneuryzma

I've changed as you suggest, the iterator declaration

Code:

---

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

---

but I still get the same error

Code:

---

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

all right, solved, thanks