为什么 和 (String)System.getProperty("line.separator");行为不同? [英] Why does and (String)System.getProperty("line.separator"); act differently?

问题描述

我的程序接受一个文本文件的输入，其中每个单词都由换行符分隔，我的程序接受它并处理数据，然后我需要输出到一个新文件，同时保持控制台输出.

现在我想知道为什么当我将 " " 附加到我的 stringBuilder 时，它会打印出来，因为它在控制台中有一个新行，但在文件输出中，它不会将它作为一个新行line 并将所有单词放在一行中.

当我使用 newLine 时，它​​只会在我的控制台输出和我的输出文件中给出一个新行.这是为什么?(String)System.getProperty("line.separator") 是什么导致了这种情况?

String newLine = (String)System.getProperty("line.separator");尝试{BufferedReader fileIn = new BufferedReader(new FileReader(fileName));stringBuilder.append(newLine);while((s = fileIn.readLine()) != null){stringBuilder.append(s);stringBuilder.append(newLine);//使用newLine，}String a = stringBuilder.toString();if(s== null){fileIn.close();}

解决方案

因为在某些系统 (Linux/Unix) 上，新行被定义为 而在其他系统 (Windows) 上它是 <代码> .根据阅读文本的软件，它可能会选择坚持这一点，或者更加宽容"地识别甚至 单独识别.

相关维基百科文本(https://en.wikipedia.org/wiki/Newline):

<块引用>

基于 ASCII 或兼容字符集的系统使用 LF(换行，' '，0x0A，十进制的 10)或 CR(回车，' '，0x0D，十进制 13)单独，或 CR 后跟 LF(CR+LF，' ', 0x0D0A)

这也是为什么您可以像以前那样从 System 类中检索系统定义的行分隔符，而不是例如将它作为 String类.

My program takes a input of a text file that has words each separated by a newline and my program takes it and deals with the data, and then I am required to output to a new file whilst keeping the console output.

Now I am wondering why when I append " " to my stringBuilder that it prints it out as it were to have a new line in the console, but in the file output, it doesn't take it as a new line and just puts all the words in one line.

When I use newLine, then only does it give a new line in both my console output and my output file. Why is that? What does (String)System.getProperty("line.separator") do that causes this?

String newLine = (String)System.getProperty("line.separator");

 try{
     BufferedReader fileIn = new BufferedReader(new FileReader(fileName));

     stringBuilder.append(newLine);
     while((s = fileIn.readLine()) != null){
        stringBuilder.append(s);
        stringBuilder.append(newLine);//using newLine, 
     }
        String a = stringBuilder.toString();

     if(s== null){
        fileIn.close();
     }

解决方案

Because on some systems (Linux/Unix) a new line is defined as while on others (Windows) it is . Depending on the software reading the text, it may chose to adhere to this or be more "forgiving" recognizing either or even individually.

Relevant Wikipedia text (https://en.wikipedia.org/wiki/Newline):

Systems based on ASCII or a compatible character set use either LF (Line feed, ' ', 0x0A, 10 in decimal) or CR (Carriage return, ' ', 0x0D, 13 in decimal) individually, or CR followed by LF (CR+LF, ' ', 0x0D0A)

This is also why you can retrieve the system-defined line separater from the System class as you did, instead of, for example, having it be some constant in the String class.

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