Pls help..Constructor,setter, getter and Exception Handling Problem

Question

halo, im new in java who learning basic thing and java.awt basic...i face some problem about constructor, setter, and getter.
1. I created a constructor, setter and getter in a file, and create another test file which would like to get the value from the constructor file.
The problem is: when i compile the test file, it come out error msg:cannot find symbol.As i know that is because i miss declare something but i dont know what i miss.I post my code here and help me to solve this problem...thanks
my constructor file...i dont know whether is correct, pls tell me if i miss something...
public class Employee{
     private int empNum;
     private String empName;
     private double empSalary;
     Employee(){
          empNum=0;
          empName="";
          empSalary=0;
     public int getEmpNum(){
          return empNum;
     public String getName(){
          return empName;
     public double getSalary(){
          return empSalary;
     public void setEmpNum(int e){
          empNum = e;
     public void setName(String n){
          empName = n;
     public void setSalary(double sal){
          empSalary = sal;
my test file....
public class TestEmployeeClass{
     public static void main(String args[]){
          Employee e = new Employee();
               e.setEmpNum(100);
               e.setName("abc");
               e.setSalary(1000.00);
               System.out.println(e.getEmpNum());
               System.out.println(e.getName());
               System.out.println(e.getSalary());
}**the program is work if i combine this 2 files coding inside one file(something like the last part of my coding of problem 2)...but i would like to separate them....*
2. Another problem is i am writing one simple program which is using java.awt interface....i would like to add a validation for user input (something like show error msg when user input character and negative number) inside public void actionPerformed(ActionEvent e) ...but i dont have any idea to solve this problem.here is my code and pls help me for some suggestion or coding about exception. thank a lots...
import java.awt.*;
import java.awt.event.*;
public class SnailTravel extends Frame implements ActionListener, WindowListener{
   private Frame frame;
   private Label lblDistance, lblSpeed, lblSpeed2, lblTime, lblTime2, lblComment, lblComment2 ;
   private TextField tfDistance;
   private Button btnCalculate, btnClear;
   public void viewInterface(){
      frame = new Frame("Snail Travel");
      lblDistance = new Label("Distance");
      lblSpeed = new Label("Speed");
      lblSpeed2 = new Label("0.0099km/h");
      lblTime = new Label("Time");
      lblTime2 = new Label("");
      lblComment = new Label("Comment");
      lblComment2 = new Label("");
      tfDistance = new TextField(20);
      btnCalculate = new Button("Calculate");
      btnClear = new Button("Clear");
      frame.setLayout(new GridLayout(5,2));
      frame.add(lblDistance);
      frame.add(tfDistance);
      frame.add(lblSpeed);
      frame.add(lblSpeed2);
      frame.add(lblTime);
      frame.add(lblTime2);
      frame.add(lblComment);
      frame.add(lblComment2);
      frame.add(btnCalculate);
      frame.add(btnClear);
      btnCalculate.addActionListener(this);
      btnClear.addActionListener(this);
      frame.addWindowListener(this);
      frame.setSize(100,100);
      frame.setVisible(true);
      frame.pack();     
    public static void main(String [] args) {
        SnailTravel st = new SnailTravel();
        st.viewInterface();
    public void actionPerformed(ActionEvent e) {
       if (e.getSource() == btnCalculate){
          SnailData sd = new SnailData();
       double distance = Double.parseDouble(tfDistance.getText());
       sd.setDistance(distance);
              sd.setSpeed(0.0099);
          sd.setTime(distance/sd.getSpeed());
          String answer = Double.toString(sd.getTime());
          lblTime2.setText(answer);
          lblComment2.setText("But No Exception!!!");
       else
       if(e.getSource() == btnClear){
          tfDistance.setText("");
          lblTime2.setText("");
   public void windowClosing(WindowEvent e){
               System.exit(1);
    public void windowClosed (WindowEvent e) { };
    public void windowDeiconified (WindowEvent e) { };
    public void windowIconified (WindowEvent e) { };
    public void windowActivated (WindowEvent e) { };
    public void windowDeactivated (WindowEvent e) { };
    public void windowOpened(WindowEvent e) { };
class SnailData{
   private double distance;
   private double speed;
   private double time;
   public SnailData(){
      distance = 0;
      speed = 0;
      time = 0;
   public double getDistance(){
      return distance;
   public double getSpeed(){
      return speed;
   public double getTime(){
      return time;
   public void setDistance(double d){
      distance = d;
   public void setSpeed(double s){
      speed = s;
   public void setTime(double t){
      time = t;
}Pls and thanks again for helps....

Answer 1

What i actually want to do is SnailTravel, but i facing some problems, which is the
- Constructor,setter, getter, and
- Exception Handling.
So i create another simple contructor files which name Employee and TestEmployeeClass, to try find out the problem but i failed, it come out error msg "cannot find symbol".
What i want to say that is if i cut below code (SnailTravel) to its own file(SnailData), SnailTravel come out error msg "cannot find symbol".So i force to put them in a same file(SnailTravel) to run properly.
I need help to separate them. (I think i miss some syntax but i dont know what)
And can somebody help me about Exception handling too pls.
class SnailData{
   private double distance;
   private double speed;
   private double time;
   public SnailData(){
      distance = 0;
      speed = 0;
      time = 0;
   public double getDistance(){
      return distance;
   public double getSpeed(){
      return speed;
   public double getTime(){
      return time;
   public void setDistance(double d){
      distance = d;
   public void setSpeed(double s){
      speed = s;
   public void setTime(double t){
      time = t;
}