Please help with file reading component

Question

i am currently writing a program in which i need to have a JTable
which displays data from a text file which can be selected from an
option via a JList. I can get the info from the file into the JTable
but for some reason which i can't figure out! the file reading method
which i have written to read the data in the text file keeps reading the text file twice so i am getting duplicate data in the JTable. it may
be easier to understand with the code i have supplied for the ListListener and the file reading method. the text file which is to be read contains data in the form - aName%anAddress%aBirthdate%aGender
here is the code:-
//class listening for JList selection
class ListListener implements ListSelectionListener{
          public void valueChanged(ListSelectionEvent e){
try{
//send the selected index to file reading method
               readFile(fileList.getSelectedIndex());
               catch(IOException exception){
               JOptionPane.showMessageDialog(
                              PeopleJTable3.this,
                              "File not found", "Error",
                              JOptionPane.ERROR_MESSAGE);
          }//end of valueChanged
//method to read a file given a specific index
public void readFile(int fileNumber)throws IOException{
          BufferedReader keyboard = new
               BufferedReader(new InputStreamReader(System.in));
PrintWriter screen = new PrintWriter(System.out, true);
//declare variables to enable separating the data in the file
String fileName, name, address, birthdate, gender, line;
int i=0;
int lineLength,firstPercent,secondPercent, thirdPercent;
PersonRecord[] group = new PersonRecord[20];
final char PERCENT = '%';
if(fileNumber == 0){
fileName = new String("datafile.txt");
//create filereader to read a byte stream from a file
//oparameter has name of file;
FileReader fr = new FileReader("datafile.txt");
//create buffered reader object takes stream of characters
//from filereader
BufferedReader in = new BufferedReader(fr);
line = in.readLine();
// while (line != null){
while( !line.equals("0")){
          //find second percentage
          firstPercent = line.indexOf(PERCENT);
          int a = firstPercent + 1;
          while(line.charAt(a) != '%'){
               a++;
//find third percentage
          secondPercent = a;
          int b = secondPercent + 1;
          while(line.charAt(b) != '%'){
               b++;
          thirdPercent = b;
          //extract the name
          name = line.substring(0,firstPercent);
          //extract the address
          address = line.substring(firstPercent + 1, secondPercent);
          //extract the D.O.B.
          birthdate = line.substring(secondPercent + 1, thirdPercent);
//extract overdraft amount;
gender = line.substring(thirdPercent + 1, line.length());
String[] tabEntry = {name,address,birthdate,gender};
//add this row to JTable
people.addRow(tabEntry);
line = in.readLine();
screen.println(i);//this was used to check that the
//file was actually being read twice
//from this method
i++;
     }//end while loop
in.close();
}//end readFile
if you can tell me why this read the file twice that would be fantastic!
Cheers
iain

Answer 1

oh, that is right... the valueChanged() method will get called twice when you use a mouseclick, but if selecting from the keyboard it will only be called once. I'm not sure why it does that either, but what camickr suggested will fix it.
Here is my substitution using the StringTokenizer..
// you will need to import the class
import java.util.StringTokenizer;
// this will actually read the entire file until EOF
while( (line = in.readLine()) != null )
     StringTokenizer st = new StringTokenizer( line, "%", false );
     // make sure there are at least 4 tokens in this line to read
     while( st.countTokens() == 4 )
          name = st.nextToken();
          address = st.nextToken();
          birthdate = st.nextToken();
          gender = st.nextToken();
     String[] tabEntry = {name,address,birthdate,gender};
     //add this row to JTable
     people.addRow(tabEntry);
} //end while loopHere's the link to the StringTokenizer's API http://java.sun.com/j2se/1.3/docs/api/java/util/StringTokenizer.html
good luck,
.kim