JavaScript escape/unescape編碼的實現

來源:互聯網
上載者:User
javascript|編碼   符合 JavaScript unescape 函數(支援Unicode)的 Java escape 編碼實現
  
  最近在弄一個跨域的互動程式,互動過程非常複雜.而且,其中一端只能使用 javascript 來處理返回.
  
  於是,發現 Java 的 URLEncoder.encode 方法與 JavaScript 的 unescape 方法已經不能相容了.
  
  現在瀏覽器的主流版本中 JavaScript 已經開始使用 Unicode 作為字串的內碼進行編碼.即, Unicode 字元 escape 之後的樣子類似於 %uABCD 而 java 的 URLEncoder.encode 方法得到的結果是 %AB%CD ,轉換出來的結果必定是亂碼了.
  
  方法有兩個,其一,用 Java 實現一個產生新編碼的方法.其二,用 JavaScript 實現一個針對舊編碼的解碼方法.想了想,還是用 Java 要方便一點點吧.
  
  上次貼出的 escape 的 java 實現,似乎對大家有用.最近曾軍同學提出 unescape 對於 javascript 與後端的互動也有意義.於是就一併實現了.再次貼上來.
  
  代碼非常簡單,注釋就免了吧.一貫的,仍然遵循"以空間換時間"原則.
  
  需要的桶子,一貫的,help yourself.

  /**
  * JavaScript escape/unescape 編碼的 Java 實現
  * 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)));
  }
  }



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