Question

我的方法存在一个小问题，应该保存JTextArea中包含的文本。当我从默认构造函数调用该方法时根本不是问题并且有效。如果我从一个带有JFileChooser的动作监听器调用该方法，我将收到以下异常（该文件已生成，但异常也被抛出）：

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 6
at text_editor.Editor.saveFile(Editor.java:186)
at text_editor.Editor.access$0(Editor.java:179)
at text_editor.Editor$SaveActionListener.actionPerformed(Editor.java:155)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2028)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2351)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.AbstractButton.doClick(AbstractButton.java:389)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:809)
at com.apple.laf.AquaMenuItemUI.doClick(AquaMenuItemUI.java:137)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:850)
at java.awt.Component.processMouseEvent(Component.java:6373)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
at java.awt.Component.processEvent(Component.java:6138)
at java.awt.Container.processEvent(Container.java:2085)
at java.awt.Component.dispatchEventImpl(Component.java:4735)
at java.awt.Container.dispatchEventImpl(Container.java:2143)
at java.awt.Component.dispatchEvent(Component.java:4565)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4621)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4282)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4212)
at java.awt.Container.dispatchEventImpl(Container.java:2129)
at java.awt.Window.dispatchEventImpl(Window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4565)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:679)
at java.awt.EventQueue.access$000(EventQueue.java:85)
at java.awt.EventQueue$1.run(EventQueue.java:638)
at java.awt.EventQueue$1.run(EventQueue.java:636)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:652)
at java.awt.EventQueue$2.run(EventQueue.java:650)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:649)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

这是我的保存方法：

private void saveFile(String path) throws IOException, BadLocationException{
    BufferedWriter buffer = null;
    try {   
        buffer = new BufferedWriter(new FileWriter(new File(path)));
        String lines[] = textfield.getText().split("\\n");

        for (int i = 0; i < this.textfield.getLineCount(); i++) {
            buffer.write(lines[i] + System.getProperty("line.separator")); 
        }
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            if (buffer != null) {
                buffer.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    JOptionPane.showMessageDialog(frame, "File saved","Information", JOptionPane.INFORMATION_MESSAGE);
}

这是JFielChooser动作听众：

private class SaveActionListener implements ActionListener{

    @Override
    public void actionPerformed(ActionEvent e) {
        try {

            final JFileChooser fc = new JFileChooser();
            int returnVal = fc.showSaveDialog(frame);

            if (returnVal == JFileChooser.APPROVE_OPTION) {
                File file = fc.getSelectedFile();
                try {
                    saveFile(file.getAbsolutePath());
                } catch (BadLocationException e1) {
                    e1.printStackTrace();
                }
            }

        } catch (IOException e1) {

            System.out.println("ERROR: Could not save ArrayList to the FileSystem");
            JOptionPane.showMessageDialog(null, "Could not save the selected file","Error", JOptionPane.ERROR_MESSAGE);
        }
    }

}

Answer 1

你得到一个ArrayIndexOutOfBoundsException，所以我想当你调用lines[i]时会抛出它：

for (int i = 0; i < this.textfield.getLineCount(); i++)

应该是：

for (int i = 0; i < lines.length; i++)

Answer 2

您的问题是，换行符拆分（“\ n”）会在TextArea上返回不同的计数，然后返回getTextLines（）。然后你会使用这样的for循环：

 for (int i = 0; i < ______this.textfield.getLineCount()  ______; i++) {
            buffer.write(lines[i] + System.getProperty("line.separator")); 
        }

用你的String []行.length字段替换this.textfield.getLineCount（）像这样：

for (int i = 0; i < lines.length; i++) {
      buffer.write(lines[i] + System.getProperty("line.separator")); 
}

java保存文件堆栈跟踪

2 个答案: