Question

Please correct the comments on the java program below

jtxtRanking.setText("Invalid marks");
JOptionPane.showMessageDialog(null, "Marks should be between 0-100", "Error", JOptionPane.ERROR_MESSAGE);
System.exit(0);
}
  
//The DefaultTableModel can be acessed through the getModel method
DefaultTableModel model = (DefaultTableModel) jTable.getModel();
  
//Add a row
model.addRow(new Object []{
  
// receive datas from the following and display it on the table
jtxtStudentID.getText(),
jcmbCourseCode.getSelectedItem(),
jtxtAverage.getText(),
jtxtRanking.getText(),
  
});

try {
FileReader fr = new FileReader(file); // read data from the file
BufferedReader br = new BufferedReader(fr); // instantiate BufferedReader object
  
DefaultTableModel model = (DefaultTableModel)jTable.getModel();
Object[] lines = br.lines().toArray(); // read the file and convert to an array
  
for(int i = 0; i < lines.length; i++){
/* The data stored on the database will be splitted
between each column by 1 space */
String[] row = lines[i].toString().split(" ");
model.addRow(row); // add the row to the table from database
}

try {
FileWriter fw = new FileWriter(file);
BufferedWriter bw = new BufferedWriter(fw);
  
// read data from the table's rows and columns
for(int i = 0; i < jTable.getRowCount(); i++){ //rows
for(int j = 0; j < jTable.getColumnCount(); j++){ //columns
// write and store the data from the table to the database
bw.write(jTable.getValueAt(i, j).toString()+" ");
}
bw.newLine(); // create new line in the database
}
  
bw.close(); // closing BufferedReader object
fw.close(); // closing FileWriter object
  
// show "Data Exported" dialog message after completion of storing data
JOptionPane.showMessageDialog(null, "Data Exported");
  

Answer 1

jtxtRanking.setText("Invalid marks");
JOptionPane.showMessageDialog(null, "Marks should be between 0-100", "Error", JOptionPane.ERROR_MESSAGE);
System.exit(0);
}
  
//The DefaultTableModel can be acessed through the getModel method

// creating 'model' fetching by method getModel()
DefaultTableModel model = (DefaultTableModel) jTable.getModel();
  
//Add a row

// receives data like(ID, Code, Average, ranking) from records and display it on the table

model.addRow(new Object []{
jtxtStudentID.getText(),
jcmbCourseCode.getSelectedItem(),
jtxtAverage.getText(),
jtxtRanking.getText(),
});

try {

// create object to read data from the file
FileReader fr = new FileReader(file);

// instantiate BufferedReader object using file object
BufferedReader br = new BufferedReader(fr);

DefaultTableModel model = (DefaultTableModel)jTable.getModel();

// read the file and convert it to an array
Object[] lines = br.lines().toArray();   

/* By following code, the data stored on the database will be splited
between each column by 1 space */
for(int i = 0; i < lines.length; i++)

{
String[] row = lines[i].toString().split(" ");

// adding the row to the table from database
model.addRow(row);
}

try {
FileWriter fw = new FileWriter(file);
BufferedWriter bw = new BufferedWriter(fw);
  
// this loop will read data from the table's rows and columns

for(int i = 0; i < jTable.getRowCount(); i++)

{

//for rows
for(int j = 0; j < jTable.getColumnCount(); j++)

{

//for columns
// write and store the data from the table to the database
bw.write(jTable.getValueAt(i, j).toString()+" ");
}

// create new line in the database
bw.newLine();
}
  

// closing BufferedReader object
bw.close();

// closing FileWriter object
fw.close();
  
// show "Data Exported" dialog message after completion of storing data
JOptionPane.showMessageDialog(null, "Data Exported");