编码问题

zh.wikipedia.org/wiki/%CE%A3 希腊字母sigama大小写问题 www.elastic.co/guide/cn/el… unicode大小写折叠

www.ibm.com/developerwo… codepoint代码点 blog.csdn.net/jackpk/arti… blog.csdn.net/u014424628/… 换行符的区别 参考有道云笔记

blog.csdn.net/huangshaoti… blog.csdn.net/u010234516/…

zh.wikipedia.org/wiki/Unicod… BMP SMP

www.ruanyifeng.com/blog/2007/1… 阮一峰utf-8编码格式

spring群讨论char为什么两个字节可以表示中文, 而utf-8中文可能会存储为多个字节.

	public static void main(String[] args) throws UnsupportedEncodingException {
		boolean matches = Pattern.matches("txt", "abc.txt");
		System.out.println(matches);
		
		String a = "a";
		String b = "好";  //597d
		char c = '好';
		System.out.println(b.getBytes("utf-8").length);
		System.out.println(b.getBytes().length);
		byte[] bytes = b.getBytes("utf-8");
		for (int i = 0; i < bytes.length; i++) {
			System.out.println(Integer.toHexString((int) bytes[i]));
		}
		
		System.out.println("==================");
		System.out.println(b.getBytes().length);
		System.out.printf("%x", (int)c);
		
		char d= '😄';
		char e= '𦡂';
		
	}