Question

I am having trouble with implementing a Parcelable class in android.

The issue i am having is that i am receiving is that BinarySearchTree cannot be cast to a TreeNode.

When i print out what the type is when i am recieving it says tree node so im not entirely sure what the issue is.

This is the error

01-31 18:13:50.986: E/AndroidRuntime(1059): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.discoverycalendar/com.discoverycalendar.DiscoveryMainMenu}: 
java.lang.ClassCastException: com.DiscoveryUtils.BinarySearchTree cannot be cast to com.DiscoveryObjects.TreeNode

private TreeNode  root = null;


@Override
public int describeContents() {

    return 0;
}

public BinarySearchTree(Parcel in){

    this();
    root = (TreeNode) in.readValue(TreeNode.class.getClassLoader());
    in.readStringList(treeCont);
    in.readStringList(treeAsString);
}

public static final Creator<BinarySearchTree> CREATOR = new Creator<BinarySearchTree>() {

    public BinarySearchTree createFromParcel(Parcel source) {

        return new BinarySearchTree(source);
    }

    public BinarySearchTree[] newArray(int size) {

        return new BinarySearchTree[size];
    }
};

@Override
public void writeToParcel(Parcel dest, int flags) {

    dest.writeValue(root);
    dest.writeStringList(treeCont);
    dest.writeStringList(treeAsString);
}

The error i am receiving is when i try casting the return value into a TreeNode. I dont know why its thinking its a different object.

Answer 1

The simple reason is TreeNode is not Serializable or Parcelable. Hence you need to make a custom class that extends TreeNode and impelemtn one of them in order to flatten the data.
Here is a document of support types. TreeNode isn’t there.