java 中 escape编码与解码

1. /** 
2.  * JavaScript escape/unescape 编码的 Java 实现 
3.  * author jackyz 
4.  * keep this copyright info while using this method by free 
5.  */  
6. public class Escape {  
7.     private final static String[] hex = {  
8.         "00","01","02","03","04","05","06","07","08","09","0A","0B","0C","0D","0E","0F",  
9.         "10","11","12","13","14","15","16","17","18","19","1A","1B","1C","1D","1E","1F",  
10.         "20","21","22","23","24","25","26","27","28","29","2A","2B","2C","2D","2E","2F",  
11.         "30","31","32","33","34","35","36","37","38","39","3A","3B","3C","3D","3E","3F",  
12.         "40","41","42","43","44","45","46","47","48","49","4A","4B","4C","4D","4E","4F",  
13.         "50","51","52","53","54","55","56","57","58","59","5A","5B","5C","5D","5E","5F",  
14.         "60","61","62","63","64","65","66","67","68","69","6A","6B","6C","6D","6E","6F",  
15.         "70","71","72","73","74","75","76","77","78","79","7A","7B","7C","7D","7E","7F",  
16.         "80","81","82","83","84","85","86","87","88","89","8A","8B","8C","8D","8E","8F",  
17.         "90","91","92","93","94","95","96","97","98","99","9A","9B","9C","9D","9E","9F",  
18.         "A0","A1","A2","A3","A4","A5","A6","A7","A8","A9","AA","AB","AC","AD","AE","AF",  
19.         "B0","B1","B2","B3","B4","B5","B6","B7","B8","B9","BA","BB","BC","BD","BE","BF",  
20.         "C0","C1","C2","C3","C4","C5","C6","C7","C8","C9","CA","CB","CC","CD","CE","CF",  
21.         "D0","D1","D2","D3","D4","D5","D6","D7","D8","D9","DA","DB","DC","DD","DE","DF",  
22.         "E0","E1","E2","E3","E4","E5","E6","E7","E8","E9","EA","EB","EC","ED","EE","EF",  
23.         "F0","F1","F2","F3","F4","F5","F6","F7","F8","F9","FA","FB","FC","FD","FE","FF"  
24.     };  
25.     private final static byte[] val = {  
26.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
27.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
28.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
29.         0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
30.         0x3F,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
31.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
32.         0x3F,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
33.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
34.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
35.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
36.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
37.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
38.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
39.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
40.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,  
41.         0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F  
42.     };  
43.     public static String escape(String s) {  
44.         StringBuffer sbuf = new StringBuffer();  
45.         int len = s.length();  
46.         for (int i = 0; i < len; i++) {  
47.             int ch = s.charAt(i);  
48.             if (ch == ' ') {                        // space : map to '+'   
49.                 sbuf.append('+');  
50.             } else if ('A' <= ch && ch <= 'Z') {    // 'A'..'Z' : as it was  
51.                 sbuf.append((char)ch);  
52.             } else if ('a' <= ch && ch <= 'z') {    // 'a'..'z' : as it was  
53.                 sbuf.append((char)ch);  
54.             } else if ('0' <= ch && ch <= '9') {    // '0'..'9' : as it was  
55.                 sbuf.append((char)ch);  
56.             } else if (ch == '-' || ch == '_'       // unreserved : as it was  
57.                 || ch == '.' || ch == '!'  
58.                 || ch == '~' || ch == '*'  
59.                 || ch == '/'' || ch == '('  
60.                 || ch == ')') {  
61.                 sbuf.append((char)ch);  
62.             } else if (ch <= 0x007F) {              // other ASCII : map to %XX  
63.                 sbuf.append('%');  
64.                 sbuf.append(hex[ch]);  
65.             } else {                                // unicode : map to %uXXXX  
66.                 sbuf.append('%');  
67.                 sbuf.append('u');  
68.                 sbuf.append(hex[(ch >>> 8)]);  
69.                 sbuf.append(hex[(0x00FF & ch)]);  
70.             }  
71.         }  
72.         return sbuf.toString();  
73.     }  
74.     public static String unescape(String s) {  
75.         StringBuffer sbuf = new StringBuffer();  
76.         int i = 0;  
77.         int len = s.length();  
78.         while (i < len) {  
79.             int ch = s.charAt(i);  
80.             if (ch == '+') {                        // + : map to ' '   
81.                 sbuf.append(' ');  
82.             } else if ('A' <= ch && ch <= 'Z') {    // 'A'..'Z' : as it was  
83.                 sbuf.append((char)ch);  
84.             } else if ('a' <= ch && ch <= 'z') {    // 'a'..'z' : as it was  
85.                 sbuf.append((char)ch);  
86.             } else if ('0' <= ch && ch <= '9') {    // '0'..'9' : as it was  
87.                 sbuf.append((char)ch);  
88.             } else if (ch == '-' || ch == '_'       // unreserved : as it was  
89.                 || ch == '.' || ch == '!'  
90.                 || ch == '~' || ch == '*'  
91.                 || ch == '/'' || ch == '('  
92.                 || ch == ')') {  
93.                 sbuf.append((char)ch);  
94.             } else if (ch == '%') {  
95.                 int cint = 0;  
96.                 if ('u' != s.charAt(i+1)) {         // %XX : map to ascii(XX)  
97.                     cint = (cint << 4) | val[s.charAt(i+1)];  
98.                     cint = (cint << 4) | val[s.charAt(i+2)];  
99.                     i+=2;  
100.                 } else {                            // %uXXXX : map to unicode(XXXX)  
101.                     cint = (cint << 4) | val[s.charAt(i+2)];  
102.                     cint = (cint << 4) | val[s.charAt(i+3)];  
103.                     cint = (cint << 4) | val[s.charAt(i+4)];  
104.                     cint = (cint << 4) | val[s.charAt(i+5)];  
105.                     i+=5;  
106.                 }  
107.                 sbuf.append((char)cint);  
108.             }  
109.             i++;  
110.         }  
111.         return sbuf.toString();  
112.     }  
113.     public static void main(String[] args) {  
114.         String stest = "黄修群1234 abcd[]()<+>,.~//";  
115.         System.out.println(stest);  
116.         System.out.println(escape(stest));  
117.         System.out.println(unescape(escape(stest)));  
118.     }  
119. }