JDBC

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost/prosoftsept
user=root
pass=1106

public class DBHelper {
    Properties prop;

    public DBHelper() {
        prop = new Properties();
        try {
            FileInputStream fis = new FileInputStream("settings.properties");
            prop.load(fis);
        } catch (FileNotFoundException ex) {
            Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public String vratiVrednosti(String key){
        return prop.getProperty(key);
    }

}
---------------DBBroker
    DBHelper dbh;
    Connection konekcija;

    public DBBroker() {
        dbh = new DBHelper();
    }

    public void ucitajDrajver(){
        try {
            Class.forName(dbh.vratiVrednosti(Konstante.DRIVER));
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(DBBroker.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public void otvoriKonekciju(){
        String url = dbh.vratiVrednosti(Konstante.URL);
        String user = dbh.vratiVrednosti(Konstante.USER);
        String pass = dbh.vratiVrednosti(Konstante.PASS);

        try {
            konekcija = DriverManager.getConnection(url, user, pass);
            konekcija.setAutoCommit(false);
        } catch (SQLException ex) {
            Logger.getLogger(DBBroker.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public void zatvoriKonekciju(){
        try {
            konekcija.close();
        } catch (SQLException ex) {
            Logger.getLogger(DBBroker.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public void commit(){
        try {
            konekcija.commit();
        } catch (SQLException ex) {
            Logger.getLogger(DBBroker.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public void rollback(){
        try {
            konekcija.rollback();
        } catch (SQLException ex) {
            Logger.getLogger(DBBroker.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
-------------
public class PokretanjeServeraNit extends Thread{

    @Override
    public void run() {
        try {
            ServerSocket ss = new ServerSocket(9000);
            System.out.println("Server on");
            while (true) {
                Socket s = ss.accept();
                System.out.println("Client on");
                ObradaKlijentskihZahteva okz = new ObradaKlijentskihZahteva(s);
                okz.start();
            }
        } catch (IOException ex) {
            Logger.getLogger(PokretanjeServeraNit.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

}
-------------
public class ObradaKlijentskihZahteva extends Thread{
    Socket s ;

    public ObradaKlijentskihZahteva(Socket s) {
        this.s = s;
    }

    @Override
    public void run() {
        KlijentskiZahtev kz = primiZahtev();
        ServerskiOdgovor so = new ServerskiOdgovor();
        switch(kz.getOperacija()){
            case

        }
        posaljiOdgovor(so);
    }

    public KlijentskiZahtev primiZahtev() {
        KlijentskiZahtev kz = new KlijentskiZahtev();
        try {
            ObjectInputStream ois = new ObjectInputStream(s.getInputStream());
            kz = (KlijentskiZahtev) ois.readObject();
        } catch (IOException ex) {
            Logger.getLogger(ObradaKlijentskihZahteva.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(ObradaKlijentskihZahteva.class.getName()).log(Level.SEVERE, null, ex);
        }
        return kz;
    }

    public void posaljiOdgovor(ServerskiOdgovor so) {
        try {
            ObjectOutputStream oos = new ObjectOutputStream(s.getOutputStream());
            oos.writeObject(so);
        } catch (IOException ex) {
            Logger.getLogger(ObradaKlijentskihZahteva.class.getName()).log(Level.SEVERE, null, ex);
        }

    }

}
-------------------------
public class KomunikacijaSaServerom {
    private static KomunikacijaSaServerom instanca;
    Socket s;

    private KomunikacijaSaServerom() {
        try {
            s = new Socket("localhost",9000);
        } catch (IOException ex) {
            Logger.getLogger(KomunikacijaSaServerom.class.getName()).log(Level.SEVERE, null, ex);
        }
    }


    public static KomunikacijaSaServerom getInstanca() {
        if(instanca == null)
            instanca = new KomunikacijaSaServerom();
        return instanca;
    }

    public ServerskiOdgovor primiOdgovor() {
        ServerskiOdgovor so = new ServerskiOdgovor();
        try {
            ObjectInputStream ois = new ObjectInputStream(s.getInputStream());
            so = (ServerskiOdgovor) ois.readObject();
        } catch (IOException ex) {
            Logger.getLogger(KomunikacijaSaServerom.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(KomunikacijaSaServerom.class.getName()).log(Level.SEVERE, null, ex);
        }
        return so;
    }

    public void posaljiZahtev(KlijentskiZahtev kz) {
        try {
            ObjectOutputStream oos = new ObjectOutputStream(s.getOutputStream());
            oos.writeObject(kz);
        } catch (IOException ex) {
            Logger.getLogger(KomunikacijaSaServerom.class.getName()).log(Level.SEVERE, null, ex);
        }

    }
}
-------------------------
public class KlijentskiZahtev implements Serializable{
    private int operacija;
    private Object parametar;

    public KlijentskiZahtev() {
    }

    public KlijentskiZahtev(int operacija, Object parametar) {
        this.operacija = operacija;
        this.parametar = parametar;
    }

    public Object getParametar() {
        return parametar;
    }

    public void setParametar(Object parametar) {
        this.parametar = parametar;
    }

    public int getOperacija() {
        return operacija;
    }

    public void setOperacija(int operacija) {
        this.operacija = operacija;
    }


}
----------------------------
public class ServerskiOdgovor implements Serializable{
    private String poruka;
    private Object odgovor;

    public ServerskiOdgovor() {
    }

    public ServerskiOdgovor(String poruka, Object odgovor) {
        this.poruka = poruka;
        this.odgovor = odgovor;
    }

    public Object getOdgovor() {
        return odgovor;
    }

    public void setOdgovor(Object odgovor) {
        this.odgovor = odgovor;
    }

    public String getPoruka() {
        return poruka;
    }

    public void setPoruka(String poruka) {
        this.poruka = poruka;
    }


}