符合 JavaScript unescape 函数(支持Unicode)的 Java escape 编码实现
最近在弄一个跨域的交互程序,交互过程非常复杂.而且,其中一端只能使用 javascript 来处理返回.

于是,发现 Java 的 URLEncoder.encode 方法与 JavaScript 的 unescape 方法已经不能兼容了.

现在浏览器的主流版本中 JavaScript 已经开始使用 Unicode 作为字符串的内码进行编码.即, Unicode 字符 escape 之后的样子类似于 %uABCD 而 java 的 URLEncoder.encode 方法得到的结果是 %AB%CD ,转换出来的结果必定是乱码了.

方法有两个,其一,用 Java 实现一个生成新编码的方法.其二,用 JavaScript 实现一个针对旧编码的解码方法.想了想,还是用 Java 要方便一点点吧.



上次贴出的 escape 的 java 实现,似乎对大家有用.最近曾军同学提出 unescape 对于 javascript 与后端的交互也有意义.于是就一并实现了.再次贴上来.

代码非常简单,注释就免了吧.一贯的,仍然遵循"以空间换时间"原则.

需要的桶子,一贯的,help yourself.

/**
* JavaScript escape/unescape 编码的 Java 实现
* author jackyz
* keep this copyright info while using this method by free
*/
public class Escape {
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"
};
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
};
public static String escape(String s) {
StringBuffer sbuf = new StringBuffer();
int len = s.length();
for (int i = 0; i < len; i++) {
int ch = s.charAt(i);
if (ch == \' \') { // space : map to \'+\'
sbuf.append(\'+\');
} else if (\'A\' <= ch && ch <= \'Z\') { // \'A\'..\'Z\' : as it was
sbuf.append((char)ch);
} else if (\'a\' <= ch && ch <= \'z\') { // \'a\'..\'z\' : as it was
sbuf.append((char)ch);
} else if (\'0\' <= ch && ch <= \'9\') { // \'0\'..\'9\' : as it was
sbuf.append((char)ch);
} else if (ch == \'-\' || ch == \'_\' // unreserved : as it was
|| ch == \'.\' || ch == \'!\'
|| ch == \'~\' || ch == \'*\'
|| ch == \'\'\' || ch == \'(\'
|| ch == \')\') {
sbuf.append((char)ch);
} else if (ch <= 0x007F) { // other ASCII : map to %XX
sbuf.append(\'%\');
sbuf.append(hex[ch]);
} else { // unicode : map to %uXXXX
sbuf.append(\'%\');
sbuf.append(\'u\');
sbuf.append(hex[(ch >>> 8)]);
sbuf.append(hex[(0x00FF & ch)]);
}
}
return sbuf.toString();
}
public static String unescape(String s) {
StringBuffer sbuf = new StringBuffer();
int i = 0;
int len = s.length();
while (i < len) {
int ch = s.charAt(i);
if (ch == \'+\') { // + : map to \' \'
sbuf.append(\' \');
} else if (\'A\' <= ch && ch <= \'Z\') { // \'A\'..\'Z\' : as it was
sbuf.append((char)ch);
} else if (\'a\' <= ch && ch <= \'z\') { // \'a\'..\'z\' : as it was
sbuf.append((char)ch);
} else if (\'0\' <= ch && ch <= \'9\') { // \'0\'..\'9\' : as it was
sbuf.append((char)ch);
} else if (ch == \'-\' || ch == \'_\' // unreserved : as it was
|| ch == \'.\' || ch == \'!\'
|| ch == \'~\' || ch == \'*\'
|| ch == \'\'\' || ch == \'(\'
|| ch == \')\') {
sbuf.append((char)ch);
} else if (ch == \'%\') {
int cint = 0;
if (\'u\' != s.charAt(i+1)) { // %XX : map to ascii(XX)
cint = (cint << 4) | val[s.charAt(i+1)];
cint = (cint << 4) | val[s.charAt(i+2)];
i+=2;
} else { // %uXXXX : map to unicode(XXXX)
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);
}
i++;
}
return sbuf.toString();
}
public static void main(String[] args) {
String stest = "中文1234 abcd[]()<+>,.~\\";
System.out.println(stest);
System.out.println(escape(stest));
System.out.println(unescape(escape(stest)));
}
}