IO流

获取指定行:

        LineNumberReader lineNumberReader = null;        try {            // 构造LineNumberReader实例            lineNumberReader = new LineNumberReader(new FileReader(                    "E:\\长软\\问题.txt"));            String line = null;            int index = 0;            while ((line = lineNumberReader.readLine()) != null) {                index = lineNumberReader.getLineNumber();                while (index > 18) {                    System.out.println("Line " + index + ": " + line);                    //重置index就可以跳出循环                    index = 0;                }            }        } catch (FileNotFoundException ex) {            ex.printStackTrace();        } catch (IOException ex) {            ex.printStackTrace();        }