如何以.txt文件格式保存和加載JTable

Question

我想知道如何以文本文件的形式保存和加載表格，以便在重新打開表格後不必將信息重新輸入到表格中。並且如果可能的話還要導出表格和一個excel文件，以便我可以在Microsoft Excel中查看。

import javax.swing.*; 
import javax.swing.table.DefaultTableModel; 
import javax.swing.table.JTableHeader; 
import javax.swing.border.LineBorder; 
import java.awt.Color; 
import java.awt.FlowLayout; 
import java.awt.Window.Type; 
import java.awt.event.ActionListener; 
import java.awt.event.ActionEvent; 
import org.eclipse.wb.swing.FocusTraversalOnArray; 
import java.awt.Component; 
import java.awt.SystemColor; 
import java.text.ParseException; 
import javax.swing.JFormattedTextField; 
import javax.swing.text.MaskFormatter; 
import java.awt.event.KeyAdapter; 
import java.awt.event.KeyEvent; 
import java.io.*; 
import java.util.ArrayList; 



public class Main extends JFrame { 
    private JTextField Searchtextfield; 
    private JTable table; 
    private JTextField Firstnametext; 
    private JTextField lastnametext; 
    private JTextField Phonenumbertext; 
    private JTextField Emailtext; 

    /** 
    * Instantiates a new main. 
    * 
    * This program allow you to store information in a table and export out and excel file 
    * or save as a text file 
    * 
    * @throws Exception the exception 
    */ 
    public Main() throws Exception { 

     getContentPane().setLayout(null); 
     JTabbedPane tabbedPane = new JTabbedPane(JTabbedPane.TOP); 
     tabbedPane.setBackground(new Color(189, 183, 107)); 
     tabbedPane.setBounds(0, 32, 650, 365); 
     getContentPane().add(tabbedPane); 
     MaskFormatter mf2 = new MaskFormatter("(###) ###-####"); 

     // the main panel that hold the search bar and table 
     JPanel MainPanel = new JPanel(); 
     MainPanel.setBackground(Color.LIGHT_GRAY); 
     tabbedPane.addTab("Main", null, MainPanel, null); 
     MainPanel.setLayout(null); 

     // the search text field 
     Searchtextfield = new JTextField(); 
     Searchtextfield.setBounds(485, 11, 129, 20); 
     MainPanel.add(Searchtextfield); 
     Searchtextfield.setColumns(10); 

     // the search label on the main panel 
     JLabel Searchlabel = new JLabel("Seach:"); 
     Searchlabel.setBounds(443, 14, 46, 14); 
     MainPanel.add(Searchlabel); 

     JScrollPane scrollPane = new JScrollPane(); 
     scrollPane.setBounds(10, 42, 604, 195); 
     MainPanel.add(scrollPane); 

     table = new JTable(); 
     table.setBorder(UIManager.getBorder("DesktopIcon.border")); 
     scrollPane.setViewportView(table); 

     // the column in the table 
     table.setModel(new DefaultTableModel(

       new Object[][] { 
      }, 
      new String[] { 
       "First Name", "Last Name", "Phone Number", "Email" 
      } 
     )); 


     // a panel that hold the first name, last name, phone number and email text field for entering 
     // information into the table on the main panel 
     JPanel AddentryPanel = new JPanel(); 
     AddentryPanel.setBackground(Color.LIGHT_GRAY); 

     // add the entry tab for inputting information 
     tabbedPane.addTab("Add Entry", null, AddentryPanel, null); 
     // set absolute layout 
     AddentryPanel.setLayout(null); 

     // a text field for entering you first name 
     Firstnametext = new JTextField(); 

     Firstnametext.setBounds(175, 49, 308, 34); 

     // add the first name text field to the add entry panel 
     AddentryPanel.add(Firstnametext); 
     Firstnametext.setColumns(10); 

     JLabel lblNewLabel = new JLabel("First Name:"); 
     lblNewLabel.setForeground(Color.BLUE); 
     lblNewLabel.setBounds(98, 59, 99, 14); 
     AddentryPanel.add(lblNewLabel); 

     JLabel Lastnamelabel = new JLabel("Last Name:"); 
     Lastnamelabel.setForeground(Color.BLUE); 
     Lastnamelabel.setBounds(98, 104, 110, 14); 
     AddentryPanel.add(Lastnamelabel); 

     // a text field for entering you last name 
     lastnametext = new JTextField(); 
     lastnametext.setColumns(10); 
     lastnametext.setBounds(175, 94, 308, 34); 

     // add the last name to the entry panel 
     AddentryPanel.add(lastnametext); 

     // add a formatted text field for you phone number. This field only allow number. 
     Phonenumbertext = new JFormattedTextField(mf2); 
     Phonenumbertext.setColumns(10); 
     Phonenumbertext.setBounds(175, 145, 308, 34); 

     // add the formatted text field to entry panel 
     AddentryPanel.add(Phonenumbertext); 

     // a text field for entering you email 
     Emailtext = new JTextField(); 
     Emailtext.setColumns(10); 
     Emailtext.setBounds(175, 190, 308, 34); 

     // add the email text field to the add entry panel 
     AddentryPanel.add(Emailtext); 

     JLabel Phonenumberlabel = new JLabel("Phone Number:"); 
     Phonenumberlabel.setForeground(Color.BLUE); 
     Phonenumberlabel.setBounds(77, 155, 93, 14); 
     AddentryPanel.add(Phonenumberlabel); 

     JLabel Email = new JLabel("Email:"); 
     Email.setForeground(Color.BLUE); 
     Email.setBounds(126, 200, 54, 14); 
     AddentryPanel.add(Email); 

     // a button that add information into the table from the first name, last name, email 
     // and you phone number field. 
     JButton AddEntrybutton = new JButton("Add"); 

     AddEntrybutton.setForeground(Color.GREEN); 

     // add a action listener for add entry button 
     AddEntrybutton.addActionListener(new ActionListener() { 
      /* 
      * This action listener for entry button will prompt 
      * you, if you want to add information into the table. 
      * It also check if all the mandatory field have been filled correctly 
      * so that it can proceed with the adding. If field has a error it will 
      * display a error. 
      */ 

      public void actionPerformed(ActionEvent e) { 

      // check if the option field are filled and correct before adding. 
       if(Firstnametext.getText().equalsIgnoreCase("")|| Phonenumbertext.getText().equalsIgnoreCase("( ) - ")){ 
        JOptionPane.showMessageDialog (null, "Make sure the the First Name and Phone Number field are filled"); 
       } 

       // prompt if you are sure you want to add these information into the table 
       else if (JOptionPane.showConfirmDialog(null, "Would you like to add these field to table?", "Request", 
         JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE) 
         == JOptionPane.YES_OPTION) 
        { 

        DefaultTableModel dtm = (DefaultTableModel)table.getModel(); 

        dtm.addRow(new Object[] { Firstnametext.getText(), lastnametext.getText(), Phonenumbertext.getText(), Emailtext.getText()}); 
        } 


      } 
     }); 
     AddEntrybutton.setBounds(175, 253, 89, 23); 

     // add the add button to the entry panel 
     AddentryPanel.add(AddEntrybutton); 


     // a button the is use for clearing the field in the add entry panel 
     JButton ClearButton = new JButton("Clear"); 
     ClearButton.setForeground(Color.RED); 
     ClearButton.addActionListener(new ActionListener() { 
      /* 
      * prompt you if you want to clear the first name, 
      * last name, phone number and email text field. 
      * if you select yes the field will be clear. 
      * if you select no the field will not be clear. 
      */ 

      public void actionPerformed(ActionEvent e) { 
       if (JOptionPane.showConfirmDialog(null, "Are you sure you want to clear the field?", "Request", 
         JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE) 
         == JOptionPane.YES_OPTION) 
        { 
        Firstnametext.setText(""); 
        lastnametext.setText(""); 
        Phonenumbertext.setText(""); 
        Emailtext.setText(""); 


        } 
        else 
        { 
        //Go back to normal 
        } 

      } 
     }); 
     ClearButton.setBounds(394, 253, 89, 23); 

     // add the clear button the entry panel 
     AddentryPanel.add(ClearButton); 

     // label tell that field is optional and doesn't need to be filled 
     JLabel Optionallabel1 = new JLabel("Optional"); 

     Optionallabel1.setBounds(493, 200, 54, 14); 
     AddentryPanel.add(Optionallabel1); 

     // label tell that field is optional and doesn't need to be filled 
     JLabel Optionallabel2 = new JLabel("Optional"); 

     Optionallabel2.setBounds(493, 104, 54, 14); 
     AddentryPanel.add(Optionallabel2); 

     // label that tell you that this field has to be filled 
     JLabel Mandatorylabel1 = new JLabel("Mandatory"); 

     Mandatorylabel1.setForeground(Color.RED); 
     Mandatorylabel1.setBounds(493, 155, 79, 14); 
     AddentryPanel.add(Mandatorylabel1); 

     // label that tell you that this field has to be filled 
     JLabel Manatorylabel2 = new JLabel("Mandatory"); 

     Manatorylabel2.setForeground(Color.RED); 
     Manatorylabel2.setBounds(493, 59, 64, 14); 
     AddentryPanel.add(Manatorylabel2); 

     // a menu bar for displaying the option to load contact, save contact, 
     // export contact as excel file and be able to close option 
     JMenuBar menuBar = new JMenuBar(); 
     menuBar.setBounds(0, 0, 650, 21); 
     getContentPane().add(menuBar); 


     JMenu fileoption = new JMenu("File"); 

     menuBar.add(fileoption); 


     JMenuItem loadcontact = new JMenuItem("Load Contact"); 

     // add load contact file to menu 
     fileoption.add(loadcontact); 

     JMenuItem savecontact = new JMenuItem("Save Contact"); 

     // add a save contact file to menu 
     fileoption.add(savecontact); 

     JMenuItem close = new JMenuItem("Close"); 
     close.addActionListener(new ActionListener() { 

      /* 
      * When selected the program will close. 
      * 
      */ 
      public void actionPerformed(ActionEvent arg0) { 
       System.exit(0); 
      } 
     }); 
     fileoption.add(close); 
     table.getColumnModel().getColumn(2).setPreferredWidth(124); 

    } 


public static void main(String[] args) throws Exception { 
     Main frame = new Main(); 
     frame.setTitle("Phone Book App"); 
     frame.setSize(640, 400); 
     frame.setLocationRelativeTo(null); // Center the frame 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.setVisible(true); 

    } 
} 

Answer 1

您可以嘗試如下操作以保存txt格式的表格內容。您還可以在.xls格式打開相同的文件太多，如果你想：

public void saveTable()throws Exception 
{ 
    BufferedWriter bfw = new BufferedWriter(new FileWriter("Data.txt")); 
    for(int i = 0 ; i < table.getColumnCount() ; i++) 
    { 
    bfw.write(table.getColumnName(i)); 
    bfw.write("\t"); 
    } 

    for (int i = 0 ; i < table.getRowCount(); i++) 
    { 
    bfw.newLine(); 
    for(int j = 0 ; j < table.getColumnCount();j++) 
    { 
     bfw.write((String)(table.getValueAt(i,j))); 
     bfw.write("\t");; 
    } 
    } 
    bfw.close(); 
}