在JTable中显示数据

Question

我想将一些数据添加到JTable并写入某个文件。数据没有被添加到表中，而是被正确写入文件。

下面是一段代码，我指的是：

import java.awt.BorderLayout; 
import java.awt.FlowLayout; 
import java.awt.GridLayout; 
import java.io.BufferedReader; 
import java.io.FileReader; 
import java.io.FileWriter; 
import java.io.IOException; 
import java.io.PrintWriter; 
import java.util.Vector; 
import javax.swing.JButton; 
import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.JPanel; 
import javax.swing.JScrollPane; 
import javax.swing.JTable; 
import javax.swing.JTextField; 
import javax.swing.table.DefaultTableModel; 

    public class Layout extends JFrame { 
     DefaultTableModel dtm; 

     public Layout() { 

     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

     p1 = new JPanel(new BorderLayout()); 
     p2 = new JPanel(new BorderLayout()); 
     p3 = new JPanel(new GridLayout(4, 2)); 
     p4 = new JPanel(new FlowLayout()); 
     p5 = new JPanel(new BorderLayout()); 

     l1 = new JLabel("Item"); 
     l2 = new JLabel("Price"); 
     l3 = new JLabel("Quantity"); 
     l4 = new JLabel("ReorderLevel"); 
     tf1 = new JTextField(); 
     tf2 = new JTextField(); 
     tf3 = new JTextField(); 
     tf4 = new JTextField(); 
     p3.add(l1); 
     p3.add(tf1); 
     p3.add(l2); 
     p3.add(tf2); 
     p3.add(l3); 
     p3.add(tf3); 
     p3.add(l4); 
     p3.add(tf4); 

     b1 = new JButton("Add"); 
     b2 = new JButton("Update"); 
     b3 = new JButton("Delete"); 
     b4 = new JButton("List"); 
     p4.add(b1); 
     p4.add(b2); 
     p4.add(b3); 
     p4.add(b4); 

     t = new JTable(); 
     t.setModel(new javax.swing.table.DefaultTableModel(
       new Object[][]{ 
        //{null, null, null, null}, 
        //{null, null, null, null}, 
        //{null, null, null, null} 
       }, 
       new String[]{ 
        "Item", "Price", "Quantity", "Reorder" 
       } 
     )); 
     sc = new JScrollPane(t); 

     p5.add(sc, BorderLayout.CENTER); 
     p2.add(p3, BorderLayout.NORTH); 
     p2.add(p4, BorderLayout.SOUTH); 
     p1.add(p2, BorderLayout.NORTH); 
     p1.add(p5, BorderLayout.CENTER); 
     add(p1); 

     pack(); 

     b1.addActionListener(new java.awt.event.ActionListener() { 
      public void actionPerformed(java.awt.event.ActionEvent evt) { 
       btnaddActionPerformed(evt); 
      } 
     } 
     ); 
    }      `add button action` 
     private void btnaddActionPerformed(java.awt.event.ActionEvent evt) 
     { 
       String item = tf1.getText(); 
       String price = tf2.getText(); 
       String quantity=tf3.getText(); 
       String reorder=tf4.getText(); 


       try { 


       String filename= "C:\\WINNT\\PROFILES\\palanisamyp\\workspace\\InventoryDBInfile\\Myfile.txt"; 


         FileWriter myfile = new FileWriter(filename,true); 

         PrintWriter outStream = new PrintWriter(myfile); 
         outStream.print(item); 
         outStream.print("|"); 
         outStream.print(price); 
         outStream.print("|"); 
         outStream.print(quantity); 
         outStream.print("|"); 
         outStream.print(reorder); 
         outStream.print("\r\n"); 
         outStream.close(); 

          tf1.setText(""); 
          tf2.setText(""); 
          tf3.setText(""); 
          tf4.setText(""); 
          myfile.close(); 

       readFile(); 



       } catch (Exception e) { 
     e.printStackTrace();} 


     } 

     private void readFile() 
     { 
       BufferedReader br = null; 

      try { 

      String sCurrentLine; 

      br = new BufferedReader(new FileReader("C:\\WINNT\\PROFILES\\palanisamyp\\workspace\\InventoryDBInfile\\Myfile.txt")); 

      if (dtm.getRowCount() > 0) { 
       for (int i = dtm.getRowCount() - 1; i > -1; i--) { 
        dtm.removeRow(i); 
       } 
      } 
      while ((sCurrentLine = br.readLine()) != null) { 

      String item1=sCurrentLine.toString(); 

      String regexp = "[|]+"; 

      String[] lines = item1.split(regexp); 

      Vector v = new Vector(); 

       String item2; 
       String price2; 
       String quantity2; 
       String reorder2; 

       item2=lines[0].toString(); 
       price2=lines[1].toString(); 
       quantity2=lines[2].toString(); 
       reorder2=lines[3].toString(); 


       v.add(item2); 
       v.add(price2); 
       v.add(quantity2); 
       v.add(reorder2); 

       dtm.toString(); 
       dtm.addRow(v); 


      } 

      } catch (IOException e) { 
      e.printStackTrace(); 
      } finally { 
      try { 
      if (br != null)br.close(); 
      } catch (IOException ex) { 
      ex.printStackTrace(); 
      } 
      } 
     } 


    public static void main(String[] args) { 
     new Layout().setVisible(true); 
    } 

    private JPanel p1, p2, p3, p4, p5; 
    private JLabel l1, l2, l3, l4; 
    private JTextField tf1, tf2, tf3, tf4; 
    private JButton b1, b2, b3, b4; 
    private JScrollPane sc; 
    private JTable t; 
} 

Answer 1

因为你分配给你表的dateModel新的DefaultTableModel

t.setModel(new javax.swing.table.DefaultTableModel(
      new Object[][]{ 
       //{null, null, null, null}, 
       //{null, null, null, null}, 
       //{null, null, null, null} 
      }, 
      new String[]{ 
       "Item", "Price", "Quantity", "Reorder" 
      } 
    )); 

而不是使用你的领域dtm

DefaultTableModel dtm; 

试试这个：

dtm = new javax.swing.table.DefaultTableModel(
       new Object[][]{ 
        //{null, null, null, null}, 
        //{null, null, null, null}, 
        //{null, null, null, null} 
       }, 
       new String[]{ 
        "Item", "Price", "Quantity", "Reorder" 
       } 
     )); 
    t.setModel(dtm); 

的

Answer 2

请检查Oracle Docs来看看如何使用模型，渲染器和编辑器中的Java表。