.get() on Map and casting to the class which is used in the Map leads to ClassCastException

Pokerkoffer commented 7 years ago

Hi, i have the following code:

Parent:

@Entity
public class Parent {
    @Id
    private String id;
    private Map<String, Child> childs;
    // getter, setter
}

Child:

@Embedded
public class Child {
    private String name;
   // getter, setter
}

Main:

public static void main(String[] args) {
    // ...
    Parent parent = new Parent();
    parent.setId("parent1");

    Child child = new Child();
    child.setName("child1");

    parent.setChilds(new HashMap<String, Child>());
    parent.getChilds().put(child.getName(), child);

    mapperTest.insertOne(parent);

     Parent parent2 = mapperTest.find().first();
     Map<String, Child> children = parent2.getChilds();
     Child child1 = children.get(child.getName()); // <- ClassCastException
}

The following Json is inserted into mongoDB:

{
    "_id" : "parent1",
    "childs" : {
        "child1" : {
            "name" : "child1"
        }
    }
}

The following code throws a ClassCastException: Exception in thread "main" java.lang.ClassCastException: org.bson.Document cannot be cast to Child

When i inspect the class parent2 (the one that is filled with the values read from the db) the values of Map childs are of type bson.Document and not Child. See screenshot below:

bildschirmfoto 2017-01-25 um 18 56 44

The same exception occurs, when I add another child. Is it possible, that the Map<String, Child> is not recognized or mapped correctly?