GUI FileViewer程序文件加载问题

Question

我目前正在开发一个java 1.4.2 GUI文件读取/保存/加密程序。因为这篇文章有500多行，我就不把全部都贴在这里了…我会张贴我有问题的部分。我遇到的问题是加密功能，其中弹出框输入您要加密的文件的名称，但无论您输入什么，在您甚至有机会输入文件名之前，您都会得到FileNotFound异常。打开和保存功能工作正常，只是加密部分。

在这里:

public void encrypt() throws IOException
{
        openWin = new JFrame("Encrypt File");
        Container openFile = openWin.getContentPane();

        JLabel L1;
        JPanel panel = new JPanel();
        JButton encryptButton;
        L1 = new JLabel ("Choose File to Encrypt: ");
        panel.add(L1);
        output = new JTextField(20);
        panel.add(output);
        encryptButton = new JButton("Encrypt File");
        encryptButton.addActionListener(this);
        panel.add(encryptButton);
        openFile.add(panel);
        openWin.setBounds(50,100,400,150);
        openWin.setVisible(true);

    //Get the current content pane
    contentPane = this.getContentPane();
    //refresh the content pane
    if(mainPanel !=null)
        contentPane.remove(mainPanel);
    //Create a new mainPanel
    mainPanel = new JPanel();
        //We need a buffered reader to read the file
    BufferedReader in = new BufferedReader(new FileReader(fileName));
    //Temp will hold heach line read in, text will be the final string
    String temp="";
    String text="";

    //read the first line
    temp = in.readLine();
    int length = temp.length();
    String encrypted = in.readLine();
    int index = temp.length() - 1;
    //loop until the file has ended
    while(index >= 0)
    {
        encrypted = encrypted + temp.charAt(index);
        index--;
        //read another line
        temp = in.readLine();
    }
    //create the text area.
    //send it (String data, height, width)
    page = new JTextArea(text,30,50);
    //Set line wrap to true, other wise it would just be one looooong line
    page.setLineWrap(true);
    //Here is where we create our scroll pane.
    scrollpane = new JScrollPane(page);

    //the page is connected to the scrollpane, the scrollpane gets connected to the mainPanel
    mainPanel.add(scrollpane);
    //The mainPanel is connected to the contentPane
    contentPane.add(mainPanel);
    //refresh the JFrame!
    validate();
}

你知道我做错了什么吗?这是我第一次使用GUI编程…

Answer 1

哪个值有'fileName'变量?也许你应该使用JFileChooser。

http://docs.oracle.com/javase/7/docs/api/javax/swing/JFileChooser.html

Answer 2

在给java文件路径时使用双斜杠吗?例如，不用

D:JavaEncryptFile.txt

应该是

D:\Java\EncryptFile.txt

因为反斜杠是Java中的转义字符