java 怎么在控制台把换行符打印出来？

Question

在windows环境下

    public static void main(String[] args) {        String b = String.format("The data download task succeed. %nName:%s ", "1");        System.out.println(b);        String a = "The data download task succeed. \r\n" +                "Name:1 ";        System.out.println(a);        System.out.println(a.equals(b));    }

运行结果为

The data download task succeed. Name:1 The data download task succeed. Name:1 true

有没有方式可以在控制台不格式化显示，而把原样的换行符打印出来，类似下面这样

The data download task succeed. \r\n Name:1 

Answer 1

通过控制台打印来看分割符是不可靠的。可以直接通过System.lineSeparator()来获取当前操作系统的换行符，然后在代码里针对不同操作系统进行特定的处理。

Answer 2

转义'\'

 String a = "The data download task succeed. \\r\\n" +                "Name:1 ";

Answer 3

不改代码就只能替换System.out了，java io 的 api 都可以这么套娃操作（装饰器模式）

    public static void main(String[] args) {        String testText = "xxx\r\n";        System.out.println(testText);        // 获取当前的 out        PrintStream oldOut = System.out;        // 在当前的 out 上包装一层，将输出内容里的特殊字符进行替换        PrintStream newOut = new PrintStream(oldOut) {            @Override            public void println(String x) {                String s = x;                if (s != null) {                    s = s.replaceAll("\n", "\\\\n");                    s = s.replaceAll("\r", "\\\\r");                }                super.println(s);            }        };        // 设置新 out        System.setOut(newOut);        System.out.println(testText);    }

Answer 4

public static void main(String[] args) {    String b = String.format("The data download task succeed. %nName:%s ", "1");    printWithEscapeSequences(b);    String a = "The data download task succeed. \r\n" +            "Name:1 ";    printWithEscapeSequences(a);    System.out.println(a.equals(b));}public static void printWithEscapeSequences(String str) {    String replaced = str.replace("\r", "\\r").replace("\n", "\\n");    System.out.println(replaced);}