今天在对接美团订单的时候，美团通过URL的get方式推送订单数据信息，在接收订单商品列表时，传的json数组形式的值，而且里面还有中文的商品名，通过request.getParameterMap()和request.getParameter(arg0)方式接收值得时候始终为空，并且报错：
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)
后来实在没办法，通过String param = request.getQueryString();进行接收值是可以的，但是需要自己进行分割，在取得detail字段时（detail就是订单商品列表字段）形式如下：
detail=[{%22app_food_code%22:%226906907501623%22,%22box_num%22:0,%22box_price%22:0,%22food_discount%22:1,%22food_name%22:%22%E7%99%BE%E4%BA%8B%E5%8F%AF%E4%B9%902L%22,%22price%22:7,%22quantity%22:1,%22sku_id%22:%226906907501623%22,%22unit%22:%22%E4%BB%BD%22},{%22app_food_code%22:%226954767413877%22,%22box_num%22:0,%22box_price%22:0,%22food_discount%22:1,%22food_name%22:%22%E5%8F%AF%E5%8F%A3%E5%8F%AF%E4%B9%902L%22,%22price%22:6.8,%22quantity%22:1,%22sku_id%22:%226954767413877%22,%22unit%22:%22%E4%BB%BD%22},{%22app_food_code%22:%226932571040748%22,%22box_num%22:0,%22box_price%22:0,%22food_discount%22:1,%22food_name%22:%22%E5%91%B3%E5%85%A8%E6%AF%8F%E6%97%A5C100%%E6%A1%83%E6%B1%81300ml%22,%22price%22:6.5,%22quantity%22:1,%22sku_id%22:%226932571040748%22,%22unit%22:%22%E4%BB%BD%22}]%20
然后我通过URLDecoder.decode(h_detail)进行转码的时候就又出了下面这个错：
java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - For input string: "u9" at java.Net.URLDecoder.decode(URLDecoder.java:173)
然后就是在网上一阵狂搜，最后终于找到了一种转码方式：
参考：http://blog.csdn.net/hbzyaxiu520/article/details/5607873
主要代码如下：
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();
}
然后直接调用：h_detail = Util.unescape(h_detail);就完成了转码，剩下的就是字符串中文乱码转码的操作了：
h_detail = new String(h_detail.getBytes("ISO-8859-1"),"UTF-8");
最后就完成了接收美团订单数据的功能。