How do I sort what data goes in which column or row when getting data from txt file and adding it to JTable

Question

For my assignment, I was told to make an application that would keep track of contracts. I have 5 rows in the JTable: ID, contract name, description, deadline and contact(s). Everything else works fine in the application, such as adding data to JTable and saving that data to a txt file, but the problem is opening the application and reading and loading the data in the txt file to the JTable.

The problem is, when I click on the 'load' button, all of the data gets put into one column, unsorted. How can I sort it in a way so that the ID goes into the id column, description goes into the description column, etc.

Here is the code:

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.FileReader;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.table.DefaultTableModel;


    public class Main {

    // Set up the size of the GUI window
    private static final int FRAME_WIDTH = 900;
    private static final int FRAME_HEIGHT = 400;
    static JTable contracts = new JTable();
    static int ID = 0;
    static String line;

    public static void main(String[] args) {

        // Set up the user interface
        final JFrame frame = new JFrame();
        final JPanel buttonPanel = new JPanel();
        frame.add(buttonPanel);
        // I need this to be able to put the buttons where I want
        buttonPanel.setLayout(null);

        // Set up Add button and its location
        final JButton buttonAdd = new JButton(" Add ");
        buttonAdd.setBounds(50, 325, 100, 20);
        buttonPanel.add(buttonAdd);


        // Set up Exit button and its location
        final JButton buttonExit = new JButton("Exit");
        buttonExit.setBounds(200, 325, 100, 20);
        buttonPanel.add(buttonExit);

        // Method for exit button
        buttonExit.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {

                System.exit(0);
            }
        });

        // Set up Save button and its location
        final JButton buttonSave = new JButton("Save");
        buttonSave.setBounds(350, 325, 100, 20);
        buttonPanel.add(buttonSave);

        // Set up Save button method
        buttonSave.addActionListener(new ActionListener(){


            public void actionPerformed(ActionEvent e) {
                try{

                    System.out.println("This works!");

                    BufferedWriter bfw = new BufferedWriter(new FileWriter("Contract_data.txt"));

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



                        for(int j = 0 ; j < contracts.getColumnCount();j++)
                        {

                            bfw.newLine();
                            bfw.write((String)(contracts.getValueAt(i,j)));
                            bfw.write("\t");;
                        }
                    }


                      bfw.close();
            }catch(Exception ex) {

                ex.printStackTrace();
            }

            }
        });
        // Set up Load button and its location
        final JButton buttonLoad =  new JButton("Load");
        buttonLoad.setBounds(500, 325, 100, 20);
        buttonPanel.add(buttonLoad);


        // Set up Labels for contracts, description, etc...
        final JLabel lblname = new JLabel("Enter contract name: ");
        lblname.setBounds(20, 5, 150, 100);
        buttonPanel.add(lblname);

        final JLabel lbldesc = new JLabel("Enter description: ");
        lbldesc.setBounds(20, 60, 150, 100);
        buttonPanel.add(lbldesc);

        final JLabel lbldeadline = new JLabel("Enter deadline: ");
        lbldeadline.setBounds(20, 115, 150, 100);
        buttonPanel.add(lbldeadline);

        final JLabel lblcontact = new JLabel("Enter contact(s):");
        lblcontact.setBounds(20, 170, 150, 100);
        buttonPanel.add(lblcontact);


        // Set up textboxes for all expected inputs
        final JTextField txtname = new JTextField();
        txtname.setBounds(180, 40, 100, 25);
        buttonPanel.add(txtname);

        final JTextField txtdesc = new JTextField();
        txtdesc.setBounds(180, 95, 100, 25);
        buttonPanel.add(txtdesc);

        final JTextField txtdeadline = new JTextField();
        txtdeadline.setBounds(180, 150, 100, 25);
        buttonPanel.add(txtdeadline);

        final JTextField txtcontact = new JTextField();
        txtcontact.setBounds(180, 210, 100, 25);
        buttonPanel.add(txtcontact);


        // Set up of columns in the table
        String[] columns = { "ID", "Contract", "Description", "Deadline", "Contact(s)" };
        // Set up of the table with the appropriate column headers
        final DefaultTableModel model = new DefaultTableModel(null, columns);

        contracts.setModel(model);
        JScrollPane scrollPane = new JScrollPane(contracts);
        scrollPane.setBounds(300, 20, 550, 300);
        buttonPanel.add(scrollPane);


        // Save button methods, including validation checking
        buttonAdd.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                if (txtname.getText().length() == 0) {
                    JOptionPane.showMessageDialog(null, "Error: no contract name");
                    return;
                }

                if (txtdesc.getText().length() == 0) {
                    JOptionPane.showMessageDialog(null, "Error: no contract description");
                    return;
                }


                // Add an ID number to each entry and add the entry to the table
                ID++;
                model.addRow(new Object[] { String.valueOf(ID),
                        txtname.getText(), txtdesc.getText(),
                        txtdeadline.getText(), txtcontact.getText() });


                // Once entry is added to the table, the text fields are cleared for the next entry
                txtname.setText("");
                txtdesc.setText("");
                txtdeadline.setText("");
                txtcontact.setText("");



            }
        });     
        // Method for load button
        buttonLoad.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {

                BufferedReader reader;
                    try{       

                        reader = new BufferedReader(new FileReader("Contract_data.txt"));
                        while((line = reader.readLine()) != null) 
                        {
                       model.addRow(new Object[] {line});

                        }
                        reader.close();
                     }
                    catch(Exception ex){ 

                ex.printStackTrace();

                    }

            }
        });
        /*
         * This sets the size of the window along with the title and it sets up
         * the exit on close X button to close the window when the X is clicked.
         */

        frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
        frame.setTitle("Contract Tracker");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

}

Please help. I would really appreciate and feedbacks.

Answer 1

when I click on the 'load' button, all of the data gets put into one column,

Look at the code for your "add" button. You add 5 pieces of data to the array.

Look at your code for the "load" button. You add 1 piece of data.

How can I sort it in a way so that the ID goes into the id column, description goes into the description column

It looks like you are trying to store the data using a tab as a delimiter. If this is the case then when you read a line of data, you need to split the line into 5 pieces of data. You can do this by using:

//model.addRow(new Object[] {line});
String[] row = line.split("\t");
model.addRow( row );