Java Unicode混淆 [英] Java Unicode Confusion
问题描述
嘿嘿，我刚刚开始尝试学习Java，并且遇到了令人困惑的事情！
HEy all, I have only just started attempting to learn Java and have run into something that is really confusing!
我正在输入书中的一个例子我我正在使用。它是为了演示
char数据类型。
I was typing out an example from the book I am using. It is to demonstrate the char data type.
代码如下：
public class CharDemo
{
public static void main(String [] args)
{
char a = 'A';
char b = (char) (a + 1);
System.out.println(a + b);
System.out.println("a + b is " + a + b);
int x = 75;
char y = (char) x;
char half = '\u00AB';
System.out.println("y is " + y + " and half is " + half);
}
}
令我困惑的是声明，char half ='\ u00AB'。该书指出\ u0000AB是符号'1/2'的代码。如上所述，当我从cmd编译并运行程序时，在该行上生成的符号实际上是'1/2'。
The bit that is confusing me is the statement, char half = '\u00AB'. The book states that \u00AB is the code for the symbol '1/2'. As described, when I compile and run the program from cmd the symbol that is produced on this line is in fact a '1/2'.
所以一切似乎都在起作用。我决定玩代码并尝试一些不同的unicodes。我搜索了多个unicode表，发现它们都没有与上面的结果一致。
So everything appears to be working as it should. I decided to play around with the code and try some different unicodes. I googled multiple unicode tables and found none of them to be consistent with the above result.
在每一个我发现它声明代码/ u00AB不是'1 / 2'实际上是这样的：
In every one I found it stated that the code /u00AB was not for '1/2' and was in fact for this:
http://www.fileformat.info/info/unic...r/ab/index.htm
那么Java使用的是什么字符集，我以为UNIode应该就是那个，Uni，只有一个。我搜索了几个小时，无处可以找到状态/ u00AB等于1/2的字符集，但这是我的java编译器将其解释为。
http://www.fileformat.info/info/unic...r/ab/index.htm So what character set is Java using, I thought UNicode was supposed to be just that, Uni, only one. I have searched for hours and nowhere can I find a character set that states /u00AB is equal to a 1/2, yet this is what my java compiler interprets it as.
我必须在这里遗漏一些明显的东西！感谢您的帮助！
I must be missing something obvious here! Thanks for any help!
推荐答案
这是Windows平台上控制台编码不匹配的一个众所周知的问题。
It's a well-known problem with console encoding mismatch on Windows platforms.
Java Runtime期望系统控制台使用的编码与系统默认编码相同。但是，Windows使用两种单独的编码： ANSI代码页（系统默认编码）和OEM代码页（控制台编码）。
Java Runtime expects that encoding used by the system console is the same as the system default encoding. However, Windows uses two separate encodings: ANSI code page (system default encoding) and OEM code page (console encoding).
因此，当您尝试将Unicode字符 U + 00AB LEFT-POINTING DOUBLE ANGLE QUOTATION MARK 写入控制台时，Java运行时期望控制台编码是ANSI编码（在你的情况下是 Windows-1252 ），这里Unicode字符表示为 0xAB 。但是，实际的控制台编码是OEM编码（在您的情况下为 CP437 ），其中 0xAB 表示½。
So, when you try to write Unicode character U+00AB LEFT-POINTING DOUBLE ANGLE QUOTATION MARK to the console, Java runtime expects that console encoding is the ANSI encoding (that is Windows-1252 in your case), where this Unicode character is represented as 0xAB. However, the actual console encoding is the OEM encoding (CP437 in your case), where 0xAB means ½.
因此，使用<$ c将数据打印到Windows控制台$ c> System.out.println（）产生错误的结果。
Therefore printing data to Windows console with System.out.println() produces wrong results.
要获得正确的结果，您可以使用 System.console（）。writer（）。println（）代替。
To get correct results you can use System.console().writer().println() instead.
这篇关于Java Unicode混淆的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
