Ave populus
ho due JSpinner, su uno cambio il valore, e il secondo prende il valore del primo, per cui ho scritto questo:
codice:
import java.sql.*;
import java.util.*;
import java.io.*;

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.event.*;

public class contabilita extends JFrame implements ChangeListener {
...
   public void StateChanged(ChangeEvent e) {
      spn_inTot.setValue(spn_in1.getValue().toString());
   }

   ...
   numModel = new SpinnerNumberModel(0.00, 0.00, 1000000.00, 0.01);  
   spn_in1 = new JSpinner();
   spn_in1.setModel(numModel);
   spn_in1.setBounds(105,5,100,20);
   spn_in1.addChangeListener(this);
   spn_in1.setEditor(new JSpinner.NumberEditor(spn_in1, "€    ###,##0.00"));              
   pnl_in.add(spn_in1);

   numModel = new SpinnerNumberModel(0.00, 0.00, 1000000.00, 0.01);  
   spn_inTot = new JSpinner();
   spn_inTot.setModel(numModel);
   spn_inTot.setBounds(105,140,100,20);
   spn_inTot.setEditor(new JSpinner.NumberEditor(spn_inTot, "€ ###,##0.00"));              
   pnl_in.add(spn_inTot);
   ...

}
ma dice:
contabilita.java:10: contabilita is not abstract and does not override abstract method stateChanged(javax.swing.event.ChangeEvent) in javax.swing.event.ChangeListener
public class contabilita extends JFrame implements ChangeListener {
^
1 error

Terminated with exit code 1