socket – How to get information from a TCP server and send it to the client in java

The idea is: I have a TCP server that calculates the amount of water in a box of water, while the latter of 250 liters must warn the customer that it must refill.
But whoever has information that the water is exhausting is the server.
How can I transmit the information so that the customer knows that it is necessary to fill with water?

My method is running.

public void execute () throws IOException {

ServerSocket Server = new ServerSocket (this.port);

System.out.println ("Open 12345 port!");

for (int i = 0; i <10; i ++) {// display a sequence of 10 random integers
quant = quant - generator.nextInt (400); // quant = 15000
System.out.println ("here indicates the quantity:" + quant);
if (quant = 250)
System.out.println ("amount of water down, fill with water");
i = 10;
}
}

while (true) {
// accept a client
Socket client = server.accept ();
System.out.println ("New client connection" + client.getInetAddress (). GetHostAddress ());
// add the client output to the list
PrintStream ps = new PrintStream (client.getOutputStream ());
this.clients.add (ps);

// create a client manager on a new thread
ClientClient tc = new ClientClient (client.getInputStream (), this);
new Thread (tc) .start ();

}
}