Java Serializing different objects

Question

I want to make a small network game of two clients sending messages to eachother. I'm new to sockets and serialization but I read that sending serialized objects via sockets is the way to do.

My problem is, I have multiple types of messages. One might be a simple chat message, the other one a turn (message) like a "NewObjectMessage" or "MoveObjectMessage"...

In tutorials I always read something like

MyClass myClass = (MyClass) objectinputstream.readObject();

which does a casting to the one specific class I put in the stream on the other side.

Question is: is there any way of determining what kind of message I get? I'm looking for something like

stream.peekObject()

or something in order to see it's type.

Or is the common way to send two messages and the first one is only a declaration telling what comes next? But what happens if some packages get mixed up and the next object is not the one I was asking for?

So what is the best way to communicate between the clients in a way of e.g. moving an object and creating an object (or writing a message etc.)?

Thanks for your help!

Nope. You need a protocol! For example, you could send a String first that describes the Object being sent? Of you could use something like STOMP which has headers, into which you can place metadata... — Boris the Spider
– Boris the Spider, Commented Jan 17, 2016 at 22:34

user207421 · Accepted Answer · 2016-01-21 20:58:12Z

2

Just read the object as an Object, and use instanceof to see what type it is.

Or have the objects all implement a common interface with an action method and just cast to the interface and call the method.

edited Jan 21, 2016 at 20:58

answered Jan 17, 2016 at 22:34

user207421

312k45 gold badges324 silver badges493 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Boris the Spider Over a year ago

Would work - bit messy if there are many different types of message.

Tobias Reich Over a year ago

Okay, so at least I might use it like an ordinary "local" object? Okay, well, at least this might work. Still, I'm not sure this is the way to do...

Tobias Reich Over a year ago

Well, since no one seems to know a better solution I vote for it. Thanks alot!

user207421 Over a year ago

@BoristheSpider if there weren't different types of message it wouldn't be necessary and the question wouldn't exist.

RaminS · Accepted Answer · 2016-01-17 22:41:25Z

0

I think what you are looking for is object.getClass().getName();.

edited Jan 17, 2016 at 22:41

answered Jan 17, 2016 at 22:36

RaminS

2,2594 gold badges24 silver badges31 bronze badges

Collectives™ on Stack Overflow

Java Serializing different objects

2 Answers 2

4 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related