在Java中正确解码用Javascript:escape()编码的中文字符

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做页面开发时使用了Javascript的escape()函数进行URL编码,如果url中有中文,结果在JSP或Servlet中用request.getParameter()时取不到参数,只返回一个空值。经过Baidu的搜索,结合我自己的工作实际,再加上网友的一些帮助,终于找到了问题所在及解决的办法。

        本来Javascript中的escape()是将中文按ISO-8859-1字符集进行URL编码的,那样通过 request.getParameter()是能直接获取到请求参数的,但后来的Javascript将escape()换成了Unicode字符集编 码,如此一来,在JSP和Servlet中就没法直接拿到请求参数了,而且此时的request获得的参数值都是空值,想了好久,也测试了不少,但是还是百思不得其解。 最后借助于网络,终于解决了此问题,我露出了灿烂的笑容☺

        解决办法:

        1、首先对中文字符进行两次escape()编码,如要传参数name,值为“黄修群”,则url的格式为....name=escape(escape("黄修群")),这样一来,在request.getParameter()就能取到编码后的参数了,但是参数去编码的形式:如下:

%u9EC4%u4FEE%u7FA4,

获得的页面参数为:获取request参数值-->%u9EC4%u4FEE%u7FA4

此时在使用java.net.URIDecoder.decode()方法,则出现解码错误,错误信息如下:

2010-5-19 15:28:03 org.apache.catalina.core.ApplicationDispatcher invoke
严重: Servlet.service() for servlet jsp threw exception
java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - For input string: "u9"
 at java.net.URLDecoder.decode(URLDecoder.java:173)
 at com.mapgis.vfd.plugins.vfdwebserver.VFDWebServer.getPageParameterList(VFDWebServer.java:674)

 

可见是解码出现了问题了

也许有人问,那我在客户端非要只用一次escape方法编码,会出现什么样的结果?请看下面:

2010-5-19 14:59:38 org.apache.tomcat.util.http.Parameters processParameters
警告: Parameters: Character decoding failed. Parameter skipped.
java.io.CharConversionException: isHexDigit
 at org.apache.tomcat.util.buf.UDecoder.convert(UDecoder.java:88)
 at org.apache.tomcat.util.buf.UDecoder.convert(UDecoder.java:49)
 at org.apache.tomcat.util.http.Parameters.urlDecode(Parameters.java:412)
 at org.apache.tomcat.util.http.Parameters.processParameters(Parameters.java:394)

。。。。。

看到上面的提示信息,可以断定是解码出现问题了,而获得的请求对象去是空的,如下:

获取request参数值-->null

 

 

        2、由于取到的参数是  u9EC4%u4FEE%u7FA4格式的,没法用常规的URLDecoder.decode()来进行解码,还好,这世上的牛人够多,在网上直接找到了一个工具类,能实现 Javascript中escape()及unescape()式的编解码,源代码如下: 

/**  * 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 = "黄修群1234 abcd[]()<+>,.~//";          System.out.println(stest);          System.out.println(escape(stest));          System.out.println(unescape(escape(stest)));      }  }  



代码运行如下:

黄修群1234 abcd[]()<+>,.~/
%u9EC4%u4FEE%u7FA41234+abcd%5B%5D()%3C%2B%3E%2C.~%5C
黄修群1234 abcd[]()<+>,.~/
黄修群

有了这个工具类,直接用Escape.unescape()方法就能将获取到的参数解码成中文格式了。

paraValue= Escape.unescape(request.getParameter(name).toString().trim());

结果输出了:黄修群

幸福吧,哈哈!


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