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！