java 从文件末尾开始读取文件内容

/**
    * 从文件末尾开始读取文件，并逐行打印
    * @param filename  file path
    * @param charset character
    */
public static void readFileFromEnd(String filename, String charset) {
    RandomAccessFile rf = null;
    try {
        rf = new RandomAccessFile(filename, "r");
        long fileLength = rf.length();
        long start = rf.getFilePointer();// 返回此文件中的当前偏移量
        long readIndex = start + fileLength -1;
        String line;
        rf.seek(readIndex);// 设置偏移量为文件末尾
        int c = -1;
        while (readIndex > start) {
            c = rf.read();
            String readText = null;
            if (c == '\n' || c == '\r') {
                line = rf.readLine();
                if (line != null) {
                    readText = new String(line.getBytes("ISO-8859-1"), charset);
                } else {
                    System.out.println("read line : " + line);
                }
                readIndex--;
            }
            readIndex--;
            rf.seek(readIndex);
            if (readIndex == 0) {// 当文件指针退至文件开始处，输出第一行
                readText = rf.readLine();
            }
            if (readText != null) {
                System.out.println(readText);
            }
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            if (rf != null)
                rf.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}