java.lang.ClassCastException: ItemAttachment cannot be cast to FileAttachment

Question

can anyone help on the below issue in EWS,

I am getting an error java.lang.ClassCastException: microsoft.exchange.webservices.data.property.complex.ItemAttachment cannot be cast to microsoft.exchange.webservices.data.property.complex.FileAttachment

    private static void readAttachment(ExchangeService service, Folder folder, int n) {
    ItemView view = new ItemView(n);
    FindItemsResults<Item> findResults;
    try {
    findResults = service.findItems(folder.getId(), view);
    System.out.println("findResults-->"+findResults.getTotalCount());


    for (Item item : findResults) {
        EmailMessage email;

            email = EmailMessage.bind(service, item.getId(), new PropertySet(BasePropertySet.IdOnly, ItemSchema.Attachments));
            System.out.println("email.getAttachments().getCount()-->"+email.getAttachments().getCount());
            //email.load();
            for (Attachment it : email.getAttachments()) {
                System.out.println(it.getName());
                FileAttachment iAttachment = (FileAttachment) it;
                //iAttachment.load( "C:\\FileLocation\\" + iAttachment .getName());
            }

    }
    } catch (ServiceLocalException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

Answer 1

Both FileAttachment and ItemAttachment are direct subclasses of Attachment class. It seams some of the attachments are instance of ItemAttachment and you are trying to cast them to FileAttachment. Since FileAttachment class is not a subclass of ItemAttachment you cannot cast to it.

With an example:

public class Animal {  }
public class Dog extends Animal { }
public class Cat extends Animal { }

Animal a = new Dog();
Cat c = (Cat)a; // this line produces ClassCastException as in your case

in this example you cannot