I’ve been using Spark Java framework in which data can be retrieved from a session like this, without any explicit type cast:

User user = req.session().attribute("user");
Item item = req.session().attribute("item");

I can

The attribute method of spark.Session looks like this:

    public <T> T attribute(String name) {
        return this.session.getAttribute(name);
    }

And the javax.servlet.http.HttpSession:

    Object getAttribute(String var1);

However when I try to reproduce this behaviour:

public class Main {
    public static void main(String[] args) {
        
    }

    public static <T> T hello(String key)  {
        return wow(key);
    }

    public static Object wow(String key)  {
        return "";
    }
}

I get an error:

java.lang.Object cannot be converted to T

How do I make my generic method work similarly to the attribute method? So that I could do

String name = hello("name");
List<String> names = hello("allnames");