用java 如何在txt 文件里 写入东西？

Question

比如说 有a.txt 文件 文件里 有 内容 然后我想在哪个原有的内容下面 添加一些 内容。请高手指教

Answer 1

new FileInputStream(new File("a.txt"),true);

Answer 2

File file = new File("xx.txt");
        InputStreamReader inputReader = null;
        BufferedReader bufferReader = null;
        OutputStream outputStream = null;
        try
        {
            InputStream inputStream = new FileInputStream(file);
            inputReader = new InputStreamReader(inputStream);
            bufferReader = new BufferedReader(inputReader);
            
            // 读取一行
            String line = null;
            StringBuffer strBuffer = new StringBuffer();
            String newLine = "\n";
            
            while ((line = bufferReader.readLine()) != null)
            {
                
                if (判断什么地方加你的东西)     
                {
                  
                }
                else
                {
                    strBuffer.append(line);
                    strBuffer.append(newLine);
                }
                
            }
            outputStream = new FileOutputStream(file);
            //写文件
            outputStream.write(strBuffer.toString().getBytes());
            
        }
        catch (IOException e)
        {
            LOG.error(e.getMessage());
        }
        finally
        {
            OtherUtilAPI.closeAll(outputStream, bufferReader, inputReader);
        }
        

Answer 3

不是上个帖子都回答了么FileWriter