Question

我有一个包含此信息的文本文件，每行信息从GUI追加到文本文件的新行：

1,Bday,12/23/1990,hills,description
2,Christmas,25/12/2018, home, presents are given and taken
3, easter,12/12/1996, inside an egg, the easter bunny is here

我希望替换某一行，因为该行以id开头，我的程序当前会删除所有数据并且不会替换任何内容。寻找有关如何修复并进行此文本行替换的答案。

private void updateEventActionPerformed(java.awt.event.ActionEvent evt) {                                            

        String id = idInput.getText();
        String eventName = nameInput.getText();
        String date = dateInput.getText();
        String location = locationInput.getText();
        String description = descriptionInput.getText();

        String newContent = (id+","+ eventName +","+ date +","+ location +","+ description);
        String oldText="";
        String line;

        try
        {
            BufferedReader br = new BufferedReader(new FileReader(events));
            BufferedWriter write = new BufferedWriter(new FileWriter(events));

            while((line = br.readLine()) != null)
            {
                oldText += line+"\r\n";
            }
            br.close();

            String update = oldText.replaceAll(String update = oldText.replaceAll(line.startsWith(id), newContent);
            write.write(update);
            write.close();

            JOptionPane.showMessageDialog(Event.this, "Event Updated");
        }
        catch(Exception err)
        {
            JOptionPane.showMessageDialog(Event.this, "Event not Updated");
            JOptionPane.showMessageDialog(Event.this, err.getMessage());   
        }        
    }

Answer 1

创建FileWrite会截断现有文件。您将首先读取文件，然后关闭FileReader并创建FileWriter，然后进行编写。

更新文本文件中的特定行

1 个答案: