package com.zhangjun.software;
/**
 * 编转码java实现类.
 */
public class Escape {

	/** The Constant hex. */
	private final static String[] hex = { "00", "01", "02", "03", "04", "05",
			"06", "07", "08", "09", "0A", "0B", "0C", "0D", "0E", "0F", "10",
			"11", "12", "13", "14", "15", "16", "17", "18", "19", "1A", "1B",
			"1C", "1D", "1E", "1F", "20", "21", "22", "23", "24", "25", "26",
			"27", "28", "29", "2A", "2B", "2C", "2D", "2E", "2F", "30", "31",
			"32", "33", "34", "35", "36", "37", "38", "39", "3A", "3B", "3C",
			"3D", "3E", "3F", "40", "41", "42", "43", "44", "45", "46", "47",
			"48", "49", "4A", "4B", "4C", "4D", "4E", "4F", "50", "51", "52",
			"53", "54", "55", "56", "57", "58", "59", "5A", "5B", "5C", "5D",
			"5E", "5F", "60", "61", "62", "63", "64", "65", "66", "67", "68",
			"69", "6A", "6B", "6C", "6D", "6E", "6F", "70", "71", "72", "73",
			"74", "75", "76", "77", "78", "79", "7A", "7B", "7C", "7D", "7E",
			"7F", "80", "81", "82", "83", "84", "85", "86", "87", "88", "89",
			"8A", "8B", "8C", "8D", "8E", "8F", "90", "91", "92", "93", "94",
			"95", "96", "97", "98", "99", "9A", "9B", "9C", "9D", "9E", "9F",
			"A0", "A1", "A2", "A3", "A4", "A5", "A6", "A7", "A8", "A9", "AA",
			"AB", "AC", "AD", "AE", "AF", "B0", "B1", "B2", "B3", "B4", "B5",
			"B6", "B7", "B8", "B9", "BA", "BB", "BC", "BD", "BE", "BF", "C0",
			"C1", "C2", "C3", "C4", "C5", "C6", "C7", "C8", "C9", "CA", "CB",
			"CC", "CD", "CE", "CF", "D0", "D1", "D2", "D3", "D4", "D5", "D6",
			"D7", "D8", "D9", "DA", "DB", "DC", "DD", "DE", "DF", "E0", "E1",
			"E2", "E3", "E4", "E5", "E6", "E7", "E8", "E9", "EA", "EB", "EC",
			"ED", "EE", "EF", "F0", "F1", "F2", "F3", "F4", "F5", "F6", "F7",
			"F8", "F9", "FA", "FB", "FC", "FD", "FE", "FF" };

	/** The Constant val. */
	private final static byte[] val = { 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x00, 0x01,
			0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
			0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F };
	/**
	 * Escape.
	 * @param s the s
	 * @return the string
	 * 编码
	 * @param s
	 * @return
	 */
	public static String escape(String s) {
		if (s != null) {
			StringBuffer sbuf = new StringBuffer();
			int len = s.length();
			for (int i = 0; i < len; i++) {
				int ch = s.charAt(i);
				if ('A' <= ch && ch <= 'Z') {
					sbuf.append((char) ch);
				} else if ('a' <= ch && ch <= 'z') {
					sbuf.append((char) ch);
				} else if ('0' <= ch && ch <= '9') {
					sbuf.append((char) ch);
				} else if (ch == '-' || ch == '_' || ch == '.' || ch == '!'
						|| ch == '~' || ch == '*' || ch == '\'' || ch == '('
						|| ch == ')') {
					sbuf.append((char) ch);
				} else if (ch <= 0x007F) {
					sbuf.append('%');
					sbuf.append(hex[ch]);
				} else {
					sbuf.append('%');
					sbuf.append('u');
					sbuf.append(hex[(ch >>> 8)]);
					sbuf.append(hex[(0x00FF & ch)]);
				}
			}
			return sbuf.toString();
		}
		return null;
	}
	/**
	 * Unescape.
	 * @param s  the s
	 * @return the string
	 * 解码 说明：本方法保证 不论参数s是否经过escape()编码，均能得到正确的“解码”结果
	 * @param s
	 * @return
	 */
	public static String unescape(String s) {
		if (s != null) {
			StringBuffer sbuf = new StringBuffer();
			int i = 0;
			int len = s.length();
			while (i < len) {
				int ch = s.charAt(i);
				if ('A' <= ch && ch <= 'Z') {
					sbuf.append((char) ch);
				} else if ('a' <= ch && ch <= 'z') {
					sbuf.append((char) ch);
				} else if ('0' <= ch && ch <= '9') {
					sbuf.append((char) ch);
				} else if (ch == '-' || ch == '_' || ch == '.' || ch == '!'
						|| ch == '~' || ch == '*' || ch == '\'' || ch == '('
						|| ch == ')') {
					sbuf.append((char) ch);
				} else if (ch == '%') {
					int cint = 0;
					if ('u' != s.charAt(i + 1)) {
						cint = (cint << 4) | val[s.charAt(i + 1)];
						cint = (cint << 4) | val[s.charAt(i + 2)];
						i += 2;
					} else {
						cint = (cint << 4) | val[s.charAt(i + 2)];
						cint = (cint << 4) | val[s.charAt(i + 3)];
						cint = (cint << 4) | val[s.charAt(i + 4)];
						cint = (cint << 4) | val[s.charAt(i + 5)];
						i += 5;
					}
					sbuf.append((char) cint);
				} else {
					sbuf.append((char) ch);
				}
				i++;
			}
			return sbuf.toString();
		}
		return null;
	}
	public static void main(String[] args) {
		Escape escape = new Escape();
		String bb = escape.escape("北京欢迎你");
		System.out.println(bb);
		System.out.println(escape.unescape(bb));
		
	}
}