是否需要将对象加载到从文本文件读取的ArrayList中并输出到JTextField？

Question

I'm working on a project and I am suppose to read in the data from a text file called "stars.txt", create objects for all the sales reps in the file, load the objects onto an ArrayList and display them into my JTextField using an enhanced for loop and formatted with the toString method. I have been at this for days and cannot get the stars.txt data to display in the JTextField!!! It compiles in NetBeans and displays the format for which I want the data in the stars.txt file to be, but not the actual data (which is salesID, firstName, lastName, osField, bsField, psField, buttonGroup1, buttonGroup2). This is all under class (JButton) displayActionButtonPerformed. I created another class called SalesReps to store the variables, sets/gets and constructor (I made this under the main class, does it matter in NetBeans I did not create a new class, ie a new TAB outside the main?) I would love any help I can get. Thanks. Heres my code:

private void displayButtonActionPerformed(java.awt.event.ActionEvent evt) { 

File file = new File("stars.txt"); 
SalesReps rep = new SalesReps(); 
ArrayList<SalesReps> aList = new ArrayList<>(); 

  try { 

    Scanner sc = new Scanner(file); 

    int sID = 0; 
    String fName = null; 
    String lName = null; 
    double oSupp = 0; 
    double bSupp = 0; 
    double pSupp = 0; 
    String button1 = null; 
    String button2 = null; 
    //SalesReps rep = null; 

    for (SalesReps aList1 : aList) { 
    System.out.println(aList1); 
    sID = sc.nextInt(); 
    fName = sc.next(); 
    lName = sc.next(); 
    oSupp = sc.nextDouble(); 
    bSupp = sc.nextDouble(); 
    pSupp = sc.nextDouble(); 
    button1 = sc.next(); 
    button2 = sc.next(); 
    rep = new SalesReps(sID, fName, lName, oSupp, bSupp, pSupp, 
          button1, button2); 
    aList.add(rep); 


 } 

      while (sc.hasNextLine()) { 
        String line = sc.nextLine(); 
        System.out.println(line); 
 } 

      sc.close(); 

  } catch (FileNotFoundException e) { 
 } 

   resultsTextArea.append(rep.toString()); 

}

 public class SalesReps { 

 private int salesID = 0; 
 private String firstName = null; 
 private String lastName= null ; 
 private double osField = 0; 
 private double bsField = 0; 
 private double psField = 0; 
 private String buttonGroup1 = null; 
 private String buttonGroup2 = null; 


 public int getSalesID() { 
 return salesID; 
} 

 public void setSalesID(int sID) { 
 salesID = sID; 
} 

 public String getFirstName() { 
 return firstName; 
} 

 public void setFirstName(String fName) { 
 firstName = fName; 
} 

 public String getLastName() { 
 return lastName; 
} 

 public void setLastName(String lName) { 
 lastName = lName; 
} 

 public double getOsField() { 
 return osField; 
} 

 public void setOsField(double oSupp) { 
 osField = oSupp; 
} 

 public double getBsField() { 
 return bsField; 
} 

 public void setBsField(double bSupp) { 
 bsField = bSupp; 
} 

 public double getPsField() { 
 return psField; 
} 

 public void setPsField(double pSupp) { 
 psField = pSupp; 
} 

 public String getButtonGroup1() { 
 return buttonGroup1; 
} 

 public void setButtonGroup1(String button1) { 
 buttonGroup1 = button1; 
} 

 public String getButtonGroup2() { 
 return buttonGroup2; 
} 

 public void setButtonGroup2(String button2) { 
 buttonGroup2 = button2; 
} 

 public SalesReps(int sID, String fName, String lName, 
                 double oSupp, double bSupp, double pSupp, String button1, 
                 String button2){ 

} 

 public SalesReps() { 
} 

 @Override 
 public String toString(){ 
 return String.format(" %s %s %s\n SUPPLIES" 
 + " %.2f \n BOOKS %.2f \n PAPER %.2f \n %s \n %s \n",salesID, 
 firstName, lastName, osField, bsField, psField, 
 buttonGroup1, buttonGroup2); 
  } 
} 

Answer 1

You're never parsing the lines from your file, this loop for (SalesReps aList1 : aList) is looping through an empty array and so it can't ever build the list. This code is saying here is an empty list, for everything in the empty list do this stuff (which of course never happens) then you just iterate through the file next. That logic should continue while your scanner has more lines. while (sc.hasNextLine()) you could do all of your parsing in this loop, by splitting up the line there. Also, you're only ever at most going to display one parse like this.

Answer 2

Use StringBuilder to concatenate the data and display it in the JTextField.

StringBuilder s = new StringBuilder();

 .
 .
 .

  for (SalesReps aList1 : aList) { 
    System.out.println(aList1); 
    sID = sc.nextInt(); 
    fName = sc.next(); 
    lName = sc.next(); 
    oSupp = sc.nextDouble(); 
    bSupp = sc.nextDouble(); 
    pSupp = sc.nextDouble(); 
    button1 = sc.next(); 
    button2 = sc.next(); 
    rep = new SalesReps(sID, fName, lName, oSupp, bSupp, pSupp, 
          button1, button2);
    aList.add(rep); 
    s.append(rep.toString());
 }
 .
 .
 .
 resultsTextArea.append(s.toString()); 

Hope is your help