Exemplo Janela Java

JFrame j = new JFrame("Janela");
        j.setSize(400,400);
        j.setLocationRelativeTo(j);
        j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel p = new JPanel();
        JLabel jLb1 = new JLabel("Digite algo: ");
        JLabel jLb2 = new JLabel("");
        JTextField jTx1 = new JTextField();
        jTx1.setPreferredSize(new Dimension( 200, 24 ));
        JButton jBt1=new JButton("Clique aqui");
        jBt1.setBounds(50,100,95,30);
        jBt1.addActionListener(new ActionListener(){

        public void actionPerformed(ActionEvent ae)
          {
           String texto = jTx1.getText();
           jLb2.setText(texto);

        }
        });

        p.add(jLb1);
        p.add(jTx1);
        p.add(jBt1);
        p.add(jLb2);
        j.add(p);
        j.setVisible(true);