文本默认写入第一行插入文本信息到文件第一行

蔚落 2023-10-10 19:02 30阅读 0赞

/**
         * 插入文件第一行(推荐)
         *
         * @param content 要插入的内容
         * @throws IOException
         */
        public static void insertAtBeginning(String filePath, String content) throws IOException {
            File file = new File(filePath);
            if (!file.exists()) {
                boolean newFile = file.createNewFile();
            }
            try (RandomAccessFile raf = new RandomAccessFile(file, "rw")) {
                byte[] originalContent = new byte[(int) raf.length()];
                raf.read(originalContent);
                raf.seek(0);
                raf.write((content + "\n").getBytes());
                raf.write(originalContent);
            }
        }
    
        /**
         * 插入文件第一行 推荐使用 insertAtBeginning
         */
        @Deprecated
        public static void writeFileToFirstLine(String filePath, String content) {
            File file = new File(filePath);
            RandomAccessFile randomAccessFile = null;
            try {
                // 读取原始文件内容
                byte[] originalContent = new byte[(int) file.length()];
                randomAccessFile = new RandomAccessFile(file, "rw");
                randomAccessFile.readFully(originalContent);
    
                // 将文件指针移到开头
                randomAccessFile.seek(0);
    
                // 写入新内容
                randomAccessFile.write(content.getBytes());
    
                // 写入原始内容
                randomAccessFile.write(originalContent);
    
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (randomAccessFile != null) {
                    try {
                        randomAccessFile.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }