IPC between Matlab and Java programs. Server process which can be started in Matlab by invoking extserver(<port>) and Java Client wich can be invoked from Java program for sending data to Matlab

Client.java

import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.util.Arrays;
import java.util.Set;


public class Client {

	public static void main(String[] args) {
		String sentence = " Y = [3,2,3,5]\n";

		byte [] b = Arrays.copyOf(sentence.getBytes(), 512);

		Socket clientSocket = null;
		try {
			clientSocket = new Socket("127.0.0.1", 30001);
		} catch (IOException e) {
			e.printStackTrace();
		}
		DataOutputStream outToServer = null;
		try {
			outToServer = new DataOutputStream(clientSocket.getOutputStream());
		} catch (IOException e) {
			e.printStackTrace();
		}
		try {
			outToServer.write(b, 0, 512);
			outToServer.flush();
		} catch (IOException e) {
			e.printStackTrace();
		}
		try {
			outToServer.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}

extserver.m

% based on http://nl.mathworks.com/matlabcentral/fileexchange/25249-tcpip-socket-communications-in-matlab-using-java-classes/content/server.m
function extserver(output_port)

import java.net.ServerSocket
import java.io.*

server_socket  = [];
output_socket  = [];

try
    
    fprintf(1, ['Waiting for client to connect to port : %d\n'], output_port);
    
    % wait for 1 second for client to connect server socket
    server_socket = ServerSocket(output_port);
    server_socket.setSoTimeout(70000);
    
    in_socket = server_socket.accept;
    
    fprintf(1, 'Client connected\n');
    
    % get a buffered data input stream from the socket
    in_stream   = in_socket.getInputStream;
    d_in_stream = DataInputStream(in_stream);
    
    pause(0.5);
    bytes_available = in_stream.available
    fprintf(1, 'Reading %d bytes\n', bytes_available)
    
    message = zeros(1, bytes_available, 'uint8');
    for i = 1:bytes_available
        message(i) = d_in_stream.readByte;
    end
    
    message = char(message)
    
    % clean up
    server_socket.close;
    in_socket.close;
catch
    if ~isempty(server_socket)
        server_socket.close
    end
    
    if ~isempty(output_socket)
        output_socket.close
    end
    
    % pause before retrying
    pause(1);
end
end