for(Object obiekt : kol){
        System.out.println(obiekt);
    }

Iterator i = kol.iterator();
    while(i.hasNext()){
        System.out.println(" "+ i.next());
        }

ArrayList kol = new ArrayList();

String a;
        a = JOptionPane.showInputDialog("Podaj pierwszy");

BufferedReader wczyt = new BufferedReader (new InputStreamReader(System.in));

 pom =wczyt.readLine();
         liczba=Integer.parseInt(pom);

double pom = Double.parseDouble(args[0]);

     args[1].equals("Celsius"))

char tab[] =s.toCharArray();

String wczyt;
        wczyt =JOptionPane.showInputDialog("Podaj ilosc marek");
        Integer ile = Integer.parseInt(wczyt);

String marka = tab[i];
char org[] =marka.toCharArray();

Random ii = new Random();



   Integer pom = ii.nextInt(25);

Arrays.sort(tab);

public Dvd(String color, String producer, double price) {
        super(producer, price);
        this.color = color;
    }

abstract public class ElectronicParts extends Product
public class ElectronicParts extends Product implements ElectronicPartsInterface

int a = new java.util.Random().nextInt(3);

        switch(a) {
            case 0: throw new Wyjatek1();
            case 1: throw new Wyjatek2();
            case 2: throw new Wyjatek3();
        }
    }

    public static void main(String[] args) {
        try {
          metoda();
        } catch (Wyjatek1 e) {
            System.out.println("Wyjatek nr : 1 ");
        } catch (Wyjatek2 e) {
            System.out.println("Wyjatek nr : 2 ");
        } catch (Wyjatek3 e) {
            System.out.println("Wyjatek nr : 3 ");
        }
    }


File plik = new File(sciezka);

 FileReader a = null;
        FileWriter b = null;
                try {
            int znak;
             long start=System.currentTimeMillis();
            a = new FileReader("la.txt");
            b= new FileWriter("lb.txt");
                while ((znak = a.read()) != -1){
                b.write(znak);
            }
                long stop=System.currentTimeMillis();
 System.out.println("Czas wykonania (w milisekundach) Readera : "+(stop-start));
        } catch (FileNotFoundException ex) {
            System.out.println("Brak Pliku");
        }

catch    (NumberFormatException e1){
            System.out.println("NumberFormatException");
            //e1.printStackTrace();
            throw e1;
    }
    catch(ArithmeticException e2){
            System.out.println("ArithmeticException");
           // e2.printStackTrace();
            throw e2;
    }
    finally

    {
            //System.out.println("Udalo sie");
    }

finally {
a.close();
b.close();
}



         FileReader aa = null;
        BufferedReader aaa = null;
         FileWriter bb = null;
         BufferedWriter bbb = null;
        try {
            int znak;
            // TODO code application logic here
            aa = new FileReader("la.txt");
            aaa = new BufferedReader(aa);

             bb= new FileWriter("lbb.txt");
            bbb = new BufferedWriter(bb);
            String line = null;
            long start2=System.currentTimeMillis();
while( (line = aaa.readLine()) != null){
                bb.write(line);
            }
long stop2=System.currentTimeMillis();
 System.out.println("Czas wykonania (w milisekundach) BufferedReader : "+(stop2-start2));

        } catch (FileNotFoundException ex) {
            System.out.println("Brak Pliku");
        }

finally {
            aa.close();
            bb.close();
            aaa.close();
            bbb.close();

}



 }

public String toString() {
        return name + telephone;
    }

Product tab[]=new Product[5];
       tab[0]=new ElectronicParts("SONY",100);
        tab[1]=new ElectronicParts("JVC",50);
        tab[2]= new Dvd("Czarny", "SONY", 250);
        tab[3]=new Dvd("Bialy", "HP", 200);
        tab[4]=new Tv(42,"Philips", 2500);



void ZglosWyjatek() throws Exception {
if (new java.util.Random().nextInt(5) == 0)
throw new Exception();
}
}
  int liczba=1;
Zad3 zad = new Zad3();
try {

zad.ZglosWyjatek ();
liczba++;


zad.ZglosWyjatek ();
liczba++;


zad.ZglosWyjatek ();
liczba++;


zad.ZglosWyjatek ();
liczba++;


zad.ZglosWyjatek ();
liczba++;


} catch (Exception e) {
    System.out.println("Wywołanie nr " + liczba + " ktore wyrzucilo wyjatek");
}


         FileReader aa = null;
        BufferedReader aaa = null;
         FileWriter bb = null;
         BufferedWriter bbb = null;
        try {
            int znak;
            // TODO code application logic here
            aa = new FileReader("la.txt");
            aaa = new BufferedReader(aa);

             bb= new FileWriter("lbb.txt");
            bbb = new BufferedWriter(bb);
            String line = null;
            long start2=System.currentTimeMillis();
while( (line = aaa.readLine()) != null){
                bb.write(line);
            }
long stop2=System.currentTimeMillis();
 System.out.println("Czas wykonania (w milisekundach) BufferedReader : "+(stop2-start2));

        } catch (FileNotFoundException ex) {
            System.out.println("Brak Pliku");
        }

finally {
            aa.close();
            bb.close();
            aaa.close();
            bbb.close();

}

 public String toString() {
        return name + telephone;

HashSet  kol = new HashSet();
 ArrayList<Student> kol = new ArrayList<Student>();
List<klasa> kol = new List<klasa> ()

public class kom implements Comparator<Student>{

    @Override
    public int compare(Student o1,Student o2){
 double srednia1 =o1.srednia(o1);
 double srednia2=o2.srednia(o2);
 if(srednia1>srednia2){
     return 1;
 }
 if(srednia1<srednia2){
     return -1;
 }
 else
     return 0;
}
}

Collections.sort(kol, new kom());
            System.out.println(kol);

//serializacja
ObjectOutputStream out = new ObjectOutputStream(
                               new BufferedOutputStream(
                                 new FileOutputStream(nazwaPliku)));

    out.writeObject(test.getCzas());
    out.close();

 ObjectInputStream in = new ObjectInputStream(
new BufferedInputStream(
new FileInputStream(nazwaPliku)));

b = (dataa) in.readObject();
       // System.out.println(b);
in.close();
System.out.println(test);

public class HelloWorld extends JFrame{
    public  HelloWorld(){

JLabel label= new JLabel("HelloWorld");
        getContentPane().add(label);


        setTitle("HellowWorldSwing");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);



 setVisible(true);
        setSize(300,300);
    }

BorderLayout border = new BorderLayout(10,10);
        setLayout(border);
 border.addLayoutComponent(label1, BorderLayout.NORTH);

public class GUI extends JFrame {
    JPanel panel = new JPanel();
    JButton b1 = new JButton("Przycisk");
    int i=0;

    GUI() {
      //  setSize(500, 400);
        setTitle("okno");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setContentPane(panel);
        panel.add(b1);

        b1.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
            i++;
            b1.setText("Wciśnięto "+i+ " razy");
            }
        }
                );
        pack();
        setVisible(true);

    }
}

public class tekstowe extends JFrame {
  JTextField tekst1;
  JTextField tekst2;
  JTextField wynik;

    tekstowe() {
        setTitle("Dodawanie");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        BorderLayout border = new BorderLayout();
       setLayout(border);
         tekst1= new JTextField();
          tekst2= new JTextField();
          wynik= new JTextField();
         JButton plus=new JButton("+");

     getContentPane().add(tekst1);
     getContentPane().add(tekst2);
       getContentPane().add(plus) ;
        getContentPane().add(wynik);


   border.addLayoutComponent(tekst1, BorderLayout.NORTH);
       border.addLayoutComponent(tekst2, BorderLayout.SOUTH);
       border.addLayoutComponent(plus, BorderLayout.WEST);
         border.addLayoutComponent(wynik, BorderLayout.EAST);

        ActionListener sl1=new Dodaj();
    plus.addActionListener(sl1);
        pack();
        setVisible(true);

    }

class Dodaj implements ActionListener
  {
    public void actionPerformed(ActionEvent zdarzenie)
    {
      long n=Integer.parseInt(tekst1.getText());
      long m=Integer.parseInt(tekst2.getText());
      long suma=n+m;
      wynik.setText(""+suma+" ");
    }
  }}