Java By Comparison

Always Check Type Before Cast

class Network {

    ObjectInputStream inputStream;
    InterCom interCom;

    void listen() throws IOException, ClassNotFoundException {
        while (true) {
            Object signal = inputStream.readObject();
            CrewMessage crewMessage = (CrewMessage) signal;
            interCom.broadcast(crewMessage);
        }
    }
}

Sometimes, you have to deal with dynamic object types at runtime. Dynamic objects can come from various sources, typically when serialized Java objects are exchanged through a channel. Before being able to use them in your program, you’ll need to explicitly cast them to a type. If you don’t do this properly, your program could crash with some kind of a RuntimeException.

In the code above, you can see a class that reads ...