java中获取系统的换行符和文件系统分隔符

楔子

java操作文件是涉及到换行符。apache.commons.io.IOUtils 中会自动获取换行符。虽然不清楚 IO jar是怎么实现的。

IOUtils中代码

    public static final String LINE_SEPARATOR_UNIX = "\n";
    /**
     * The Windows line separator string.
     */
    public static final String LINE_SEPARATOR_WINDOWS = "\r\n";
    /**
     * The system line separator string.
     */
    public static final String LINE_SEPARATOR;

    static {
        // avoid security issues
        StringBuilderWriter buf = new StringBuilderWriter(4);
        PrintWriter out = new PrintWriter(buf);
        out.println();
        LINE_SEPARATOR = buf.toString();
        out.close();
    }

测试

    public static void main(String[] args) {
        ////////////////////////////////////////////

        char DIR_SEPARATOR = File.separatorChar;
        System.out.println("文件系统分隔符"+DIR_SEPARATOR);
        /////////////////////////////////////////////
        StringBuilderWriter buf = new StringBuilderWriter(4);
        PrintWriter out = new PrintWriter(buf);
        out.println();
        String LINE_SEPARATOR = buf.toString();
        if (IOUtils.LINE_SEPARATOR_UNIX.equals(LINE_SEPARATOR)) {
            System.out.println("Linux 换行符");

        } else if (IOUtils.LINE_SEPARATOR_WINDOWS.equals(LINE_SEPARATOR)) {
            System.out.println("window  换行符");
        }
        out.close();
    }