Java Socket - Client-server Communication Stuck With Multi-threading

Firstly, my code is just a demo of my multiplayer game (2 or more players can play simultaneously) to demonstrate my problem without any extra things. I have successfully implemented peer-to-peer (P2P) communication in my game. Later, I decided to add support for client-server communication (ie a central server which is also a player) in my game. It should be much easier than P2P. Now here is the problem:

Suppose, I have 1 server and some clients (may be 1 or more clients). They all should give the following output:

Starting...
A
B
C
E
F
...
...
Done!

They all give the above output without using multi-thread. But using multi-threading, it gives the above output only when there're 1 server and 1 client. I'm using 2 threads (1 for sending, 1 for receiving) for each Socket. That means, each client has only 2 threads for communication but the server has (2 * totalClients) threads.

I've attached my full test project. So, here I'm only showing my 2 thread classes.

ReceiveThread class:
class ReceiveThread extends Thread {
private ObjectInputStream receiveStream;
private BlockingQueue<Character> queue = new ArrayBlockingQueue<Character>(Common.totalClients);

[Code] ....

Since I've attached my full test project, I'm not showing the other 3 classes. They are ServerMain, ClientMain and Common. If I've 2 clients to be connected, then I get the following output:

Server: (Runs first)

Starting...
A
Client 1 (clientID is 1): (Runs after the server)

Starting...
A
B
B
Client 2 (clientID is 2): (Runs after Client 1)

Starting...
A

They are stuck at there, even no exception. Actually, the server and the clients are stuck at the line try { ch = queue.take(); } if more than 1 client are connected. It seems that all are trying to receive data. But without using the dedicated threads, they all work as expected even for more than 1 client. Why is this behaviour? How to solve it? Note that I have used the same SendThread and ReceiveThread classes by which I have succcessfully implemented P2P communication.

About my attached test project file:

It has 5 small .java files for the classes as stated above. It is currently faulty when using additional threads. You have to change clientID variable for each client (they are described inside). But it works as expected without additional threads. To test it without the additional threads:

Comment " TODO" linesUncomment the single lines just after " TODO" linesComment the additional thread construction lines (4 lines)

Currently, for a workaround, I'm not using the dedicated threads for sending and receiving data only for client-server communication in my multi-player game. But I'm still using these threads for P2P communication. I don't know why it is and how to solve it.This is the attached test project file as described above.

Attached File(s) : Test Project.zip (4.11K)