Question

I have an object in my code of the type Object:
Object o

The class of the instance is Object: o.getClass() gives Object.

Now, it should be a Map! How can I upcast this to a Map?

I tried: Map<String, Object> map = (HashMap<String,Object>)o

But this returns:
java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to java.util.HashMap

The instance ‘o’ comes from a XMLRPC request. This request does not qualify variables correctly supposedly

Please have a look at this!?

EDIT:

Now I have the following issue:
o.getClass().getName() gives java.util.ArrayList,

o.get(0) gives [Ljava.lang.Object;@739e8329,

and o.get(0).getClass().getName() gives java.lang.String.

I cannot findout what to do..

EDIT2:

Finally I found out what happened. The software that created this object flattened a datastructure into a String (valueOf()). So, when I printed the variable it returned a [Ljava.util.Object, which was in fact a String containing this information.

Thanks guys!

Answer 1

[Ljava.lang.Object indicates the type of the object o is an array of Objects – that is Object[]. You cannot cast it to Map.

You might find it useful if took a look at: java: what is this: [Ljava.lang.Object;?

You stated that .getClass() indicated Object, but was it Object or [LObject?
Compare to:

    Object[] array= new Object[]{};
    Object simple = new Object();

    System.out.println(array.getClass());
    System.out.println(simple.getClass());      

which prints:

class [Ljava.lang.Object;
class java.lang.Object