Java decompor notas

//esta classe decompõe o valor digitado em notas. import javax.swing.*; import java.awt.*; import java.awt.event.*; public class decompornotas extends JanelaJFrame implements ActionListener{ JButton limpar; JButton calcular; JButton voltar; JLabel titulo, valor1, texto1, exibir, n1,n2,n3,n4,n5,n6,n7, v1,v2,v3,v4,v5,v6,v7, imagem; JTextField t1; Color a = new Color(140,200,111); Color a1 = new Color(126,180,131); //construtor Container tela = getContentPane(); public decompornotas(){ super("DECOMPOR"); setLayout (null); tela.setBackground(Color.WHITE);

//exibindo o título titulo = new JLabel ("DECOMPOR NOTAS"); titulo.setBounds(140,15,400,20); titulo.setFont(new Font("arial",Font.BOLD,24)); titulo.setForeground(a); tela.add(titulo); //Pedir número Label + caixa de texto valor1 = new JLabel ("DIGITE O VALOR:"); valor1.setBounds(50,67,150,20); valor1.setFont(new Font("arial",Font.BOLD,14)); valor1.setForeground(Color.BLACK); tela.add(valor1); t1 = new JTextField (); t1.setBounds(190,67,180,20); t1.setFont(new Font("arial",Font.PLAIN,12)); t1.setBorder(BorderFactory.createLineBorder(a,1)); t1.setForeground(Color.BLACK); tela.add(t1); //quantidade de notas v1 = new JLabel ("0",JLabel.RIGHT); v1.setBounds(250,123,35,20); v1.setFont(new Font("arial",Font.PLAIN,20)); v1.setForeground(a); tela.add(v1); v2 = new JLabel ("0",JLabel.RIGHT); v2.setBounds(250,143,35,20); v2.setFont(new Font("arial",Font.PLAIN,20)); v2.setForeground(a); tela.add(v2); v3 = new JLabel ("0",JLabel.RIGHT); v3.setBounds(250,163,35,20); v3.setFont(new Font("arial",Font.PLAIN,20)); v3.setForeground(a); tela.add(v3); v4 = new JLabel ("0",JLabel.RIGHT); v4.setBounds(250,183,35,20); v4.setFont(new Font("arial",Font.PLAIN,20)); v4.setForeground(a); tela.add(v4); v5 = new