如何在JTextField中使用bufferedreader時顯示Java中的文件路徑？

Question

Select File Dialog Box when Pressing a select button

After selecting a file

我需要的文件的絕對路徑是在文本框中。但整個文件內容都在JTextField。

這裏是我的全碼：

public class NewWork 
{ 
    public JFrame Frame; 
    public JLabel textLabel; 
    public JButton readButton, writeButton, printButton; 
    public JTextField textField; 
    public FileReader reader; 
    public FileWriter writer; 
    public BufferedReader br; 
    public BufferedWriter bw; 

    public void PrintFrame()  
    { 
     Frame = new JFrame(); 
     Frame.setSize(500, 300); 
     //Frame.pack(); 
     Frame.setBackground(Color.BLUE); 

     textLabel = new JLabel(); 
     textLabel.setText("Selected File Path:"); 
     textLabel.setBounds(30, 30, 300, 30); 
     textLabel.setVisible(true); 

     textField = new JTextField(); 
     textField.setBounds(30, 70, 300, 30); 
     textField.setVisible(true); 

     readButton = new JButton(); 
     readButton.setBounds(350, 70, 100, 30); 
     readButton.setText("Select File"); 
     readButton.setVisible(true); 
     readButton.addActionListener(new ActionListener() 
     { 
      public void actionPerformed(ActionEvent e) 
      { 
      JFileChooser FileChooser = new JFileChooser(); 
      FileChooser.showOpenDialog(null); 
      File f= FileChooser.getSelectedFile(); 
      String path= f.getAbsolutePath(); 
      try 
      { 
       reader = new FileReader(path); 
       br = new BufferedReader(reader); 
       textField.read(br, null); 
       br.close(); 
       textField.requestFocus(); 
      } 
      catch(Exception e1) 
      { 
       JOptionPane.showMessageDialog(null, e1); 
       // Check Later 
       JOptionPane.showMessageDialog(FileChooser, e1); 
      } 
      } 
     }); 

     writeButton = new JButton(); 
     writeButton.setBounds(30, 130, 100, 30); 
     writeButton.setText("Write"); 
     writeButton.setVisible(true); 
     writeButton.addActionListener(new ActionListener() 
     { 
      public void actionPerformed(ActionEvent e) 
      { 
      try 
      { 
       writer = new FileWriter("E://new.txt"); 
       bw = new BufferedWriter(writer); 
       textField.write(bw); 
       bw.close(); 
       textField.setText(""); 
       textField.requestFocus(); 
      } 
      catch(Exception e2) 
      { 
       JOptionPane.showMessageDialog(null, e2); 
      } 
      } 
     }); 

     printButton = new JButton(); 
     printButton.setBounds(190, 130, 100, 30); 
     printButton.setText("Print Setup"); 
     printButton.setVisible(true); 
     printButton.addActionListener(new ActionListener() 
     { 
      public void actionPerformed(ActionEvent e) 
      { 
      try 
      { 
       boolean complete = textField.print(); 
       if(complete) 
       { 
        JOptionPane.showMessageDialog(null, "Done Printing!"); 
       } 
       else 
       { 
        JOptionPane.showMessageDialog(null, " Printing!"); 
       } 
      } 
      catch(Exception e3) 
      { 
       JOptionPane.showMessageDialog(null, e3); 
      } 
      } 
     }); 

     Frame.add(textLabel); 
     Frame.add(textField); 
     Frame.add(readButton); 
     //Frame.add(writeButton); 
     Frame.add(printButton); 
     Frame.setLayout(null); 
     Frame.setLocationRelativeTo(null); 
     Frame.setVisible(true); 
     Frame.setResizable(false); 
     // 

    } 
    public static void main(String[] args) 
    { 
     NewWork nw = new NewWork(); 
     nw.PrintFrame(); 
     //System.out.println("Hi"); 
    } 
} 

Answer 1

這...

reader = new FileReader(path); 
br = new BufferedReader(reader); 
textField.read(br, null); 
br.close(); 
textField.requestFocus(); 

將讀取整個文件內容爲JTextField，這顯然不是你想要做什麼。

相反，你要當你準備好採取文件的路徑，並把它放入JTextField，但使用一個實例字段來跟蹤所選文件的...

private File selectedFile; 
//... 
selectedFile = null; 
JFileChooser FileChooser = new JFileChooser(); 
if (FileChooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) { 
    selectedFile = FileChooser.getSelectedFile(); 
    String path= f.getAbsolutePath(); 
    textField.setText(path); 
} 

然後複製/寫，你可以使用類似文件...

if (selectedFile != null) { 

    try { 
     Files.copy(
      selectedFile.toPath(), 
      new File("E:/new.txt").toPath(), 
      StandardCopyOption.REPLACE_EXISTING); 
    } catch (IOException ex) { 
     ex.printStackTrace(); 
    } 

} 

看一看Copying a File or Directory更多細節