TextListeners and arrays

Question

Ok i'm working throught this online tutorial for java and almost done. I worked through a program that has u create a lotto game, u can use quick pick or enter ur own numbers. It runs the game until u get 6 out of 6 numbers. then u can play again. Now the winning numbers which the computer generates a random number 1-50 is a TextField array. and user numbers is assigned by TextField[ ] numbers = new TextField[6]. What i am having probs with is that i'm suppose to use the textlistener to detemine if the user enters the numbers that it is a number between 1-50 and not allow the game to start... this is all i can think of and it doesn't work
numbers.addTextListener();
this i get an cannot resolve symbol, but only happens when i try to add
a listener to an array
public void textValueChanged(TextEvent txt)
this i'm just getting confused on how i'm using the argument
any advice

Answer 1

ok i got the text listener to work , it compiles it runs but anytime a textfield is set to null i get a long list of exception in the background about java.lang.NumberFormatException: for input string: " "
here is all my code cause i don't know what u need.. sorry little messy
import java.awt.*;
import java.awt.event.*;
import java.awt.event.TextListener.*;
public class LottoMadness extends java.applet.Applet implements ItemListener, ActionListener, TextListener, Runnable
Thread playing;
Panel row1 = new Panel();
CheckboxGroup option = new CheckboxGroup();      
Checkbox quickpick = new Checkbox("Quick Pick", option, false);     
Checkbox personal = new Checkbox("Personal", option, false);
Panel row2 = new Panel();
Label numbersLabel = new Label("Your picks: ", Label.RIGHT);
TextField[] numbers = new TextField[6];
Label winnerLabel = new Label("Winners: ", Label.RIGHT);
TextField[] winners = new TextField[7]; //array for 6 textfields to declare winning numbers, 1 for slowdown
TextField slowDown = winners[6];
Panel row3 = new Panel();
Button stop = new Button("Stop");
Button play = new Button("Play");
Button reset = new Button("Reset");
Panel row4 = new Panel();
Label got3Label = new Label("3 of 6: ", Label.RIGHT);
TextField got3 = new TextField();
Label got4Label = new Label("4 of 6: ", Label.RIGHT);
TextField got4 = new TextField();
Label got5Label = new Label("5 of 6: ", Label.RIGHT);
TextField got5 = new TextField(); //creates text field next to 5 of 6
Label got6Label = new Label("6 of 6: ", Label.RIGHT);
TextField got6 = new TextField(); //creates text field next to 6 of 6
Label drawingsLabel = new Label("Drawings: ", Label.RIGHT);
TextField drawings = new TextField(); //creates text field next to drawings
Label yearsLabel = new Label("Years: ", Label.RIGHT);
TextField years = new TextField(); //creates text field next to years
public void init()
setBackground(Color.lightGray);
GridLayout appletLayout = new GridLayout(5, 1, 10, 10);
setLayout(appletLayout);
//add Listeners
quickpick.addItemListener(this);
personal.addItemListener(this);
stop.addActionListener(this);
play.addActionListener(this);
reset.addActionListener(this);
FlowLayout layout1 = new FlowLayout(FlowLayout.CENTER, 10, 10);
row1.setLayout(layout1); //associates layout1 with Panel row1
row1.add(quickpick); //adds quickpick to row1
row1.add(personal); //adds personal to row1
add(row1); //adds row1 to applet
GridLayout layout2 = new GridLayout(2, 7, 10, 10);
row2.setLayout(layout2);
row2.add(numbersLabel);
for(int i = 0; i < 6; i++)
numbers[i] = new TextField();
row2.add(numbers);           
for(int i = 0; i < 6; i++)
numbers[i].addTextListener(this);
row2.add(winnerLabel); //adds winnerLabel to row2
for(int i = 0; i < 6; i++)
winners[i] = new TextField(); //sets up new TextField object
winners[i].setEditable(false); //does not allow user to edit this text box
row2.add(winners[i]); //adds each of the text boxes next to winners
add(row2); //adds row2 to applet
FlowLayout layout3 = new FlowLayout(FlowLayout.CENTER, 10, 10);
row3.setLayout(layout3); //associates layout3 with Panel row3
stop.setEnabled(false);
row3.add(stop); //adds stop button to row3
row3.add(play); //adds play button to row3
row3.add(reset); //adds reset button to row3
add(row3); //adds row3 to applet
GridLayout layout4 = new GridLayout(2, 2, 20, 10);
row4.setLayout(layout4); //associates layout4 with Panel row4
row4.add(got3Label); //add got3Label to row4
got3.setEditable(false); //don't allow user to edit it
row4.add(got3); //add textfield got3 to row4
row4.add(got4Label); //ect same as above
got4.setEditable(false);
row4.add(got4);
row4.add(got5Label);
got5.setEditable(false);
row4.add(got5);
row4.add(got6Label);
got6.setEditable(false);
row4.add(got6);
row4.add(drawingsLabel);
drawings.setEditable(false);
row4.add(drawings);
row4.add(yearsLabel);
years.setEditable(false);
row4.add(years);
add(row4); //add row4 to applet
public void actionPerformed(ActionEvent event) //if an action occurs from a button event info sent here
String command = event.getActionCommand(); //id's the component responsible for event
if(command == "Reset") //if component is Reset jump to clearAllFields() method
clearAllFields();
if(command == "Play") //if is Play
playing = new Thread(this); //create new thread object
playing.start(); //start game
play.setEnabled(false); //since game started play button not needed
stop.setEnabled(true); //since game started stop button should be available
reset.setEnabled(false); //since game running reset not needed
quickpick.setEnabled(false); //since game running quickpick or personal should not be able to be selected
personal.setEnabled(false);
if(command == "Stop") //if stop
playing.stop(); //stop game
stop.setEnabled(false);
play.setEnabled(true);
reset.setEnabled(true);
quickpick.setEnabled(true);
personal.setEnabled(true);
public void itemStateChanged(ItemEvent event)      
String command = (String) event.getItem(); //determines which item is picked
if(command == "Quick Pick")
for(int i = 0; i < 6; i++)
int pick; //variable to hold the random number picked
do
pick = (int)Math.floor(Math.random() * 50 + 1);                
while(numberGone(pick, numbers, i)); //create random number until this is no longer true from numberGone method
numbers[i].setText("" + pick); //sets the number text field to random numbers picked
else //if quick pick is not selected set all number text fields to null so user can enter the numbers
for(int i = 0; i < 6; i++)
numbers[i].setText(null);
public void textValueChanged(TextEvent txt)
Object source = txt.getSource();
for(int i = 0; i < 6; i++)
if(source == numbers[i])
int newNumber = Integer.parseInt(numbers[i].getText());
if(newNumber < 1 || newNumber > 50)
numbers[i].setText(null);
play.setEnabled(false);
void clearAllFields()
for(int i = 0; i < 6; i++)
numbers[i].setText(null);
winners[i].setText(null);
got3.setText(null);
got4.setText(null);
got5.setText(null);
got6.setText(null);
drawings.setText(null);
years.setText(null);
void addOneToField(TextField field)
int num = Integer.parseInt("0" + field.getText()); //get current number from field. 0 if nothing is there
num++; //adds one to number
field.setText("" + num); //displayes new number in field
boolean numberGone(int num, TextField[] pastNums, int count)
for(int i = 0; i < count; i++)           
if(Integer.parseInt(pastNums[i].getText()) == num)
     return true;
     return false;
boolean matchedOne(TextField win, TextField[] allPicks)
for(int i = 0; i < 6; i++)
String winText = win.getText(); //gets number computer picks
if(winText.equals(allPicks[i].getText())) //sees if that number is equal to any numbers that user(or quick pick) picked
return true; //if computer number matches any of user numbers return true
return false; //if none were the same return false
public void run()
while(true)
addOneToField(drawings); //add one to drawings field
int draw = Integer.parseInt(drawings.getText()); //gets the number in the drawing field
float numYears = (float)draw/104; //divides that number by 104, to assume 104 lotto drawings are played in one year
years.setText("" + numYears); //sets numYears to the answer to display number of years playing lotto
int matches = 0; //variable for number of matches made
for(int i = 0; i < 7; i++)
if(winners[i] == slowDown) //is new textField is equal to winner[6] (right after all numbers are picked for this round)
try{Thread.sleep(500);} catch(InterruptedException e){} //pause
break; //break from loop since winner[6] has no real values given to it
int ball; //variable which is goin to hold the numbers the computer generates
do
ball = (int)Math.floor(Math.random() * 50 + 1); //creates random number 1 - 50
while(numberGone(ball, winners, i)); //make sure random number is not the same as any other ones for this drawing
winners[i].setText("" + ball); //set random number to winners[i] textfield
if(matchedOne(winners[i], numbers)) //if there was a match
matches++; //add one to matches
switch(matches)
case 3:
addOneToField(got3); //if 3 were matched add 1 to got3 field
break;
case 4:
addOneToField(got4); //if 4 were matched add 1 to got4 field
break;
case 5:
addOneToField(got5); //if 5 were matched add 1 to got5 field
break;
case 6:
addOneToField(got6); //if 6 were matched add 1 to got6 field
stop.setEnabled(false);           
play.setEnabled(true); //allow user to press play button
playing.stop(); //stop applet