Java从csv读取并显示在jTable上

Question

我一直坚持从 csv 中读回，我成功地创建了 csv。我面临的问题是我无法获得有关如何获取从 csv 返回到 jTable 的值的线索。除了 public void fromCsv

之外，我没有遇到任何其他问题

  class FCMS extends JFrame{
    String header[] = {"Firstname","Lastname","FCMS ID","Email"};
    String data[][];
    DefaultTableModel model = new DefaultTableModel(data, header);
    JTable table = new JTable(model);
    JPanel pane = new JPanel();
    JPanel pane_input = new JPanel();
    JLabel lbl_firstname = new JLabel(" Firstname");
    JLabel lbl_lastname = new JLabel(" Lastname");
        JLabel lbl_id = new JLabel(" FCMS ID");
    JLabel lbl_email = new JLabel(" Email");
    JTextField txt_firstname = new JTextField(10);
    JTextField txt_lastname = new JTextField(10);
        JTextField txt_id = new JTextField(10);
    JTextField txt_email = new JTextField(10);
    JButton btn_add = new JButton("Add Entry");
    JButton btn_Csv = new JButton("Export to Csv");
        JButton btn_load = new JButton("Load From Csv");

    public FCMS(){
        setSize(200,200);
        setPreferredSize(new Dimension(350,300));
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setLocationRelativeTo(null);
        setResizable(true);
        setTitle("Flight Crew Management System");

        btn_add.setMnemonic(KeyEvent.VK_A);
        btn_Csv.setMnemonic(KeyEvent.VK_E);
                btn_load.setMnemonic(KeyEvent.VK_L);

        pane_input.setLayout(new GridLayout(0,2));
        pane_input.add(lbl_firstname);
        pane_input.add(txt_firstname);
        pane_input.add(lbl_lastname);
        pane_input.add(txt_lastname);
                pane_input.add(lbl_id);
                pane_input.add(txt_id);
        pane_input.add(lbl_email);
        pane_input.add(txt_email);
                pane_input.add(btn_add);
        pane_input.add(btn_Csv);        
                pane_input.add(btn_load);

        pane.setLayout(new BorderLayout());
        pane.add(pane_input, BorderLayout.NORTH);
        pane.add(new JScrollPane(table), BorderLayout.CENTER);

        add(pane);
        pack();
        setVisible(true);

        btn_add.addActionListener(new AksyonListener());
        btn_Csv.addActionListener(new AksyonListener());
                btn_load.addActionListener(new AksyonListener());
        txt_email.addActionListener(new AksyonListener());
    }

    public void toCsv(JTable table, File file){
        try{
                TableModel model = table.getModel();
                FileWriter Csv = new FileWriter(file);


                for(int i = 0; i < model.getColumnCount(); i++){
                        Csv.write(model.getColumnName(i) + ",");
                }

                Csv.write("\n");

                for(int i=0; i< model.getRowCount(); i++) {
                        for(int j=0; j < model.getColumnCount(); j++) {
                                Csv.write(model.getValueAt(i,j).toString()+",");
                        }
                        Csv.write("\n");
                }

                Csv.close();
        }catch(IOException e){ System.out.println(e); }
    }

    public void fromCsv(File file){

        BufferedReader fileReader = null;
        model.setRowCount(0);

        try{

                 //Create the file reader
                fileReader = new BufferedReader(new FileReader(file));

                //Read the CSV file header to skip it
                fileReader.readLine();

                int fn = 0;
                int ln = 1;
                 int id = 2;
                int email = 3;


                String line="";
                 //Read the file line by line starting from the second line
                while ((line = fileReader.readLine()) != null) {
                    //Get all tokens available in line
                    String[] tokens = line.split(",");
                    model.insertRow(model.getRowCount(), new Object[]{Long.parseLong(tokens[fn]), tokens[ln], tokens[id], tokens[email]});
                 //   if (tokens.length > 0) {

                 //   }
                }


                 /*  for(int i=0; i< tokens.length; i++) {
                            for(int j=0; j < tokens.length; j++) {
                                //Csv.read(model.getValueAt(i,j).toString()+"\t");
                                model.insertRow(model.getRowCount(), new Object[]{Long.parseLong(tokens[fn]), tokens[ln], tokens[id], tokens[email]});
                            }
                           // Csv.read("\n");
                    }*/

                fileReader.close();

        }catch (Exception e) {
            System.out.println("Error in CsvFileReader !!!");
            e.printStackTrace();
        }

    }

    public static void main(String[] args){
        new FCMS();
    }

    class AksyonListener implements ActionListener{
        public void actionPerformed(ActionEvent e){
            if(e.getSource() == btn_add || e.getSource() == txt_email){
                    String fn = txt_firstname.getText();
                    String ln = txt_lastname.getText();
                    String id = txt_id.getText();
                    String mail = txt_email.getText();

                    txt_firstname.setText("");
                    txt_lastname.setText("");
                    txt_id.setText("");
                    txt_email.setText("");
                    txt_firstname.requestFocus();

                    model.insertRow(model.getRowCount(), new Object[]{fn, ln, id, mail});
            }
            else if(e.getSource() == btn_Csv){

                JFileChooser fc = new JFileChooser();
                int option = fc.showSaveDialog(FCMS.this);

                if(option == JFileChooser.APPROVE_OPTION){
                    String filename = fc.getSelectedFile().getName(); 
                    String path = fc.getSelectedFile().getParentFile().getPath();

                    int len = filename.length();
                    String ext = "";
                    String file = "";

                        if(len > 4){
                                ext = filename.substring(len-4, len);
                        }

                        if(ext.equals(".csv")){
                                file = path + "\\" + filename; 
                        }else{
                                file = path + "\\" + filename + ".csv"; 
                        }
                    toCsv(table, new File(file));
                }
            }
            else if(e.getSource() == btn_load){

                JFileChooser fc = new JFileChooser();
                int option = fc.showOpenDialog(FCMS.this);

                if(option == JFileChooser.APPROVE_OPTION){
                        String filename = fc.getSelectedFile().getName(); 
                        String path = fc.getSelectedFile().getParentFile().getPath();

                        int len = filename.length();
                        String ext = "";
                        String file = "";

                            if(len > 4){
                                    ext = filename.substring(len-4, len);
                            }

                            if(ext.equals(".csv")){
                                    file = path + "\\" + filename; 
                            }else{
                                    file = path + "\\" + filename + ".csv"; 
                            }

                        fromCsv(new File(file));

                    }
            }
        }
    }
}

问题已解决:

try{

                 //Create the file reader
                fileReader = new BufferedReader(new FileReader(file));

                //Read the CSV file header to skip it
                fileReader.readLine();

                int fn = 0;
                int ln = 1;
                int id = 2;
                int email = 3;


                String line="";
                 //Read the file line by line starting from the second line
                while ((line = fileReader.readLine()) != null) {
                    //Get all tokens available in line
                    String[] tokens = line.split(",");
                    model.insertRow(model.getRowCount(), new Object[]{(tokens[fn]), tokens[ln], tokens[id], tokens[email]});
                 //   if (tokens.length > 0) {

                 //   }
                }


                 /*  for(int i=0; i< tokens.length; i++) {
                            for(int j=0; j < tokens.length; j++) {
                                //Csv.read(model.getValueAt(i,j).toString()+"\t");
                                model.insertRow(model.getRowCount(), new Object[]{Long.parseLong(tokens[fn]), tokens[ln], tokens[id], tokens[email]});
                            }
                           // Csv.read("\n");
                    }*/

                fileReader.close();

        }

Answer 1

String[] tokens = line.split(",");

上面是将一行数据拆分为一个数组的位置，因此上面是您需要从数组中获取数据并将其添加到 TableModel 的位置。

所以你的代码应该是:

String[] tokens = line.split(",");
model.insertRow(model.getRowCount(), new Object[]{Long.parseLong(tokens[fn]), tokens[ln], tokens[id], tokens[email]});

那么就不需要第二次循环了。

但是，上面的代码只是将数据追加到现有的“模型”中，因此您可能还需要清除模型中的所有数据。您可以通过添加以下内容来做到这一点:

model.setRowCount(0);

循环之前。