Again: help with Java program

[el-half]

DataConnect is a class I wrote:

class DataConnect {     //class for transfer of image
	
	Socket socket = null;
	BufferedInputStream buffer = null;
	DataInputStream data_reader = null;
	String address = "192.168.1.3";
	int PORTNUM;
	
	public DataConnect(int port) {
	    PORTNUM = port;
    }
    
    void establishConnection() {
    	
    	try {
    		socket = new Socket(address, PORTNUM);
    		buffer = new BufferedInputStream(socket.getInputStream());
    		data_reader = new DataInputStream(buffer);
        } catch (IOException e) {
        	System.err.println("Exception: " + e.getMessage());
        	System.exit(1);
        }
    }
}